diff --git a/crates/cargo-test-support/src/compare.rs b/crates/cargo-test-support/src/compare.rs
index 5b5d4b6ce85..b05bc42b996 100644
--- a/crates/cargo-test-support/src/compare.rs
+++ b/crates/cargo-test-support/src/compare.rs
@@ -45,8 +45,11 @@ use crate::cross_compile::try_alternate;
 use crate::paths;
 use crate::{diff, rustc_host};
 use anyhow::{bail, Result};
+use snapbox::Data;
+use snapbox::IntoData;
 use std::fmt;
 use std::path::Path;
+use std::path::PathBuf;
 use std::str;
 use url::Url;
 
@@ -428,46 +431,6 @@ fn substitute_macros(input: &str) -> String {
     result
 }
 
-/// Compares one string against another, checking that they both match.
-///
-/// See [Patterns](index.html#patterns) for more information on pattern matching.
-///
-/// - `description` explains where the output is from (usually "stdout" or "stderr").
-/// - `other_output` is other output to display in the error (usually stdout or stderr).
-pub(crate) fn match_exact(
-    expected: &str,
-    actual: &str,
-    description: &str,
-    other_output: &str,
-    cwd: Option<&Path>,
-) -> Result<()> {
-    let expected = normalize_expected(expected, cwd);
-    let actual = normalize_actual(actual, cwd);
-    let e: Vec<_> = expected.lines().map(WildStr::new).collect();
-    let a: Vec<_> = actual.lines().map(WildStr::new).collect();
-    if e == a {
-        return Ok(());
-    }
-    let diff = diff::colored_diff(&e, &a);
-    bail!(
-        "{} did not match:\n\
-         {}\n\n\
-         other output:\n\
-         {}\n",
-        description,
-        diff,
-        other_output,
-    );
-}
-
-/// Convenience wrapper around [`match_exact`] which will panic on error.
-#[track_caller]
-pub(crate) fn assert_match_exact(expected: &str, actual: &str) {
-    if let Err(e) = match_exact(expected, actual, "", "", None) {
-        crate::panic_error("", e);
-    }
-}
-
 /// Checks that the given string contains the given lines, ignoring the order
 /// of the lines.
 ///
@@ -706,6 +669,136 @@ impl fmt::Debug for WildStr<'_> {
     }
 }
 
+pub struct InMemoryDir {
+    files: Vec<(PathBuf, Data)>,
+}
+
+impl InMemoryDir {
+    pub fn paths(&self) -> impl Iterator<Item = &Path> {
+        self.files.iter().map(|(p, _)| p.as_path())
+    }
+
+    #[track_caller]
+    pub fn assert_contains(&self, expected: &Self) {
+        use std::fmt::Write as _;
+        let assert = assert_e2e();
+        let mut errs = String::new();
+        for (path, expected_data) in &expected.files {
+            let actual_data = self
+                .files
+                .iter()
+                .find_map(|(p, d)| (path == p).then(|| d.clone()))
+                .unwrap_or_else(|| Data::new());
+            if let Err(err) =
+                assert.try_eq(Some(&path.display()), actual_data, expected_data.clone())
+            {
+                let _ = write!(&mut errs, "{err}");
+            }
+        }
+        if !errs.is_empty() {
+            panic!("{errs}")
+        }
+    }
+}
+
+impl<P, D> FromIterator<(P, D)> for InMemoryDir
+where
+    P: Into<std::path::PathBuf>,
+    D: IntoData,
+{
+    fn from_iter<I: IntoIterator<Item = (P, D)>>(files: I) -> Self {
+        let files = files
+            .into_iter()
+            .map(|(p, d)| (p.into(), d.into_data()))
+            .collect();
+        Self { files }
+    }
+}
+
+impl<const N: usize, P, D> From<[(P, D); N]> for InMemoryDir
+where
+    P: Into<PathBuf>,
+    D: IntoData,
+{
+    fn from(files: [(P, D); N]) -> Self {
+        let files = files
+            .into_iter()
+            .map(|(p, d)| (p.into(), d.into_data()))
+            .collect();
+        Self { files }
+    }
+}
+
+impl<P, D> From<std::collections::HashMap<P, D>> for InMemoryDir
+where
+    P: Into<PathBuf>,
+    D: IntoData,
+{
+    fn from(files: std::collections::HashMap<P, D>) -> Self {
+        let files = files
+            .into_iter()
+            .map(|(p, d)| (p.into(), d.into_data()))
+            .collect();
+        Self { files }
+    }
+}
+
+impl<P, D> From<std::collections::BTreeMap<P, D>> for InMemoryDir
+where
+    P: Into<PathBuf>,
+    D: IntoData,
+{
+    fn from(files: std::collections::BTreeMap<P, D>) -> Self {
+        let files = files
+            .into_iter()
+            .map(|(p, d)| (p.into(), d.into_data()))
+            .collect();
+        Self { files }
+    }
+}
+
+impl From<()> for InMemoryDir {
+    fn from(_files: ()) -> Self {
+        let files = Vec::new();
+        Self { files }
+    }
+}
+
+macro_rules! impl_from_tuple_for_dirsnapshot {
+    ($($var:ident $path:ident $data:ident),+) => {
+        impl<$($path: Into<PathBuf>, $data: IntoData),+> From<($(($path, $data)),+ ,)> for InMemoryDir {
+            fn from(files: ($(($path, $data)),+,)) -> Self {
+                let ($($var),+ ,) = files;
+                let files = [$(($var.0.into(), $var.1.into_data())),+];
+                files.into()
+            }
+        }
+    };
+}
+
+macro_rules! impl_from_tuples_for_dirsnapshot {
+    ($var1:ident $path1:ident $data1:ident, $($var:ident $path:ident $data:ident),+) => {
+        impl_from_tuples_for_dirsnapshot!(__impl $var1 $path1 $data1; $($var $path $data),+);
+    };
+    (__impl $($var:ident $path:ident $data:ident),+; $var1:ident $path1:ident $data1:ident $(,$var2:ident $path2:ident $data2:ident)*) => {
+        impl_from_tuple_for_dirsnapshot!($($var $path $data),+);
+        impl_from_tuples_for_dirsnapshot!(__impl $($var $path $data),+, $var1 $path1 $data1; $($var2 $path2 $data2),*);
+    };
+    (__impl $($var:ident $path:ident $data:ident),+;) => {
+        impl_from_tuple_for_dirsnapshot!($($var $path $data),+);
+    }
+}
+
+impl_from_tuples_for_dirsnapshot!(
+    s1 P1 D1,
+    s2 P2 D2,
+    s3 P3 D3,
+    s4 P4 D4,
+    s5 P5 D5,
+    s6 P6 D6,
+    s7 P7 D7
+);
+
 #[cfg(test)]
 mod test {
     use snapbox::assert_data_eq;
diff --git a/crates/cargo-test-support/src/diff.rs b/crates/cargo-test-support/src/diff.rs
index cd0c9738553..8b5e109be45 100644
--- a/crates/cargo-test-support/src/diff.rs
+++ b/crates/cargo-test-support/src/diff.rs
@@ -16,99 +16,6 @@ pub enum Change<T> {
     Keep(usize, usize, T),
 }
 
-pub fn diff<'a, T>(a: &'a [T], b: &'a [T]) -> Vec<Change<&'a T>>
-where
-    T: PartialEq,
-{
-    if a.is_empty() && b.is_empty() {
-        return vec![];
-    }
-    let mut diff = vec![];
-    for (prev_x, prev_y, x, y) in backtrack(&a, &b) {
-        if x == prev_x {
-            diff.push(Change::Add(prev_y + 1, &b[prev_y]));
-        } else if y == prev_y {
-            diff.push(Change::Remove(prev_x + 1, &a[prev_x]));
-        } else {
-            diff.push(Change::Keep(prev_x + 1, prev_y + 1, &a[prev_x]));
-        }
-    }
-    diff.reverse();
-    diff
-}
-
-fn shortest_edit<T>(a: &[T], b: &[T]) -> Vec<Vec<usize>>
-where
-    T: PartialEq,
-{
-    let max = a.len() + b.len();
-    let mut v = vec![0; 2 * max + 1];
-    let mut trace = vec![];
-    for d in 0..=max {
-        trace.push(v.clone());
-        for k in (0..=(2 * d)).step_by(2) {
-            let mut x = if k == 0 || (k != 2 * d && v[max - d + k - 1] < v[max - d + k + 1]) {
-                // Move down
-                v[max - d + k + 1]
-            } else {
-                // Move right
-                v[max - d + k - 1] + 1
-            };
-            let mut y = x + d - k;
-            // Step diagonally as far as possible.
-            while x < a.len() && y < b.len() && a[x] == b[y] {
-                x += 1;
-                y += 1;
-            }
-            v[max - d + k] = x;
-            // Return if reached the bottom-right position.
-            if x >= a.len() && y >= b.len() {
-                return trace;
-            }
-        }
-    }
-    panic!("finished without hitting end?");
-}
-
-fn backtrack<T>(a: &[T], b: &[T]) -> Vec<(usize, usize, usize, usize)>
-where
-    T: PartialEq,
-{
-    let mut result = vec![];
-    let mut x = a.len();
-    let mut y = b.len();
-    let max = x + y;
-    for (d, v) in shortest_edit(a, b).iter().enumerate().rev() {
-        let k = x + d - y;
-        let prev_k = if k == 0 || (k != 2 * d && v[max - d + k - 1] < v[max - d + k + 1]) {
-            k + 1
-        } else {
-            k - 1
-        };
-        let prev_x = v[max - d + prev_k];
-        let prev_y = (prev_x + d).saturating_sub(prev_k);
-        while x > prev_x && y > prev_y {
-            result.push((x - 1, y - 1, x, y));
-            x -= 1;
-            y -= 1;
-        }
-        if d > 0 {
-            result.push((prev_x, prev_y, x, y));
-        }
-        x = prev_x;
-        y = prev_y;
-    }
-    return result;
-}
-
-pub fn colored_diff<'a, T>(a: &'a [T], b: &'a [T]) -> String
-where
-    T: PartialEq + fmt::Display,
-{
-    let changes = diff(a, b);
-    render_colored_changes(&changes)
-}
-
 pub fn render_colored_changes<T: fmt::Display>(changes: &[Change<T>]) -> String {
     // anstyle is not very ergonomic, but I don't want to bring in another dependency.
     let red = anstyle::AnsiColor::Red.on_default().render();
@@ -140,27 +47,3 @@ pub fn render_colored_changes<T: fmt::Display>(changes: &[Change<T>]) -> String
     }
     String::from_utf8(buffer.into_inner()).unwrap()
 }
-
-#[cfg(test)]
-pub fn compare(a: &str, b: &str) {
-    let a: Vec<_> = a.chars().collect();
-    let b: Vec<_> = b.chars().collect();
-    let changes = diff(&a, &b);
-    let mut result = vec![];
-    for change in changes {
-        match change {
-            Change::Add(_, s) => result.push(*s),
-            Change::Remove(_, _s) => {}
-            Change::Keep(_, _, s) => result.push(*s),
-        }
-    }
-    assert_eq!(b, result);
-}
-
-#[test]
-fn basic_tests() {
-    compare("", "");
-    compare("A", "");
-    compare("", "B");
-    compare("ABCABBA", "CBABAC");
-}
diff --git a/crates/cargo-test-support/src/publish.rs b/crates/cargo-test-support/src/publish.rs
index a1c7f04e4cd..e6adac7d048 100644
--- a/crates/cargo-test-support/src/publish.rs
+++ b/crates/cargo-test-support/src/publish.rs
@@ -57,15 +57,15 @@
 //! );
 //! ```
 
-use crate::compare::assert_match_exact;
+use crate::compare::InMemoryDir;
 use crate::registry::{self, alt_api_path, FeatureMap};
 use flate2::read::GzDecoder;
 use snapbox::prelude::*;
-use std::collections::{HashMap, HashSet};
+use std::collections::HashSet;
 use std::fs;
 use std::fs::File;
 use std::io::{self, prelude::*, SeekFrom};
-use std::path::{Path, PathBuf};
+use std::path::Path;
 use tar::Archive;
 
 fn read_le_u32<R>(mut reader: R) -> io::Result<u32>
@@ -85,7 +85,7 @@ pub fn validate_upload(expected_json: &str, expected_crate_name: &str, expected_
         expected_json,
         expected_crate_name,
         expected_files,
-        &[],
+        (),
     );
 }
 
@@ -94,7 +94,7 @@ pub fn validate_upload_with_contents(
     expected_json: &str,
     expected_crate_name: &str,
     expected_files: &[&str],
-    expected_contents: &[(&str, &str)],
+    expected_contents: impl Into<InMemoryDir>,
 ) {
     let new_path = registry::api_path().join("api/v1/crates/new");
     _validate_upload(
@@ -118,7 +118,7 @@ pub fn validate_alt_upload(
         expected_json,
         expected_crate_name,
         expected_files,
-        &[],
+        (),
     );
 }
 
@@ -127,7 +127,7 @@ fn _validate_upload(
     expected_json: &str,
     expected_crate_name: &str,
     expected_files: &[&str],
-    expected_contents: &[(&str, &str)],
+    expected_contents: impl Into<InMemoryDir>,
 ) {
     let (actual_json, krate_bytes) = read_new_post(new_path);
 
@@ -174,7 +174,22 @@ pub fn validate_crate_contents(
     reader: impl Read,
     expected_crate_name: &str,
     expected_files: &[&str],
-    expected_contents: &[(&str, &str)],
+    expected_contents: impl Into<InMemoryDir>,
+) {
+    let expected_contents = expected_contents.into();
+    validate_crate_contents_(
+        reader,
+        expected_crate_name,
+        expected_files,
+        expected_contents,
+    )
+}
+
+fn validate_crate_contents_(
+    reader: impl Read,
+    expected_crate_name: &str,
+    expected_files: &[&str],
+    expected_contents: InMemoryDir,
 ) {
     let mut rdr = GzDecoder::new(reader);
     assert_eq!(
@@ -189,7 +204,7 @@ pub fn validate_crate_contents(
             .strip_suffix(".crate")
             .expect("must end with .crate"),
     );
-    let files: HashMap<PathBuf, String> = ar
+    let actual_contents: InMemoryDir = ar
         .entries()
         .unwrap()
         .map(|entry| {
@@ -205,7 +220,7 @@ pub fn validate_crate_contents(
             (name, contents)
         })
         .collect();
-    let actual_files: HashSet<&Path> = files.keys().map(|p| p.as_path()).collect();
+    let actual_files: HashSet<&Path> = actual_contents.paths().collect();
     let expected_files: HashSet<&Path> =
         expected_files.iter().map(|name| Path::new(name)).collect();
     let missing: Vec<&&Path> = expected_files.difference(&actual_files).collect();
@@ -216,15 +231,7 @@ pub fn validate_crate_contents(
             missing, extra
         );
     }
-    if !expected_contents.is_empty() {
-        for (e_file_name, e_file_contents) in expected_contents {
-            let e_file_name = Path::new(e_file_name);
-            let actual_contents = files
-                .get(e_file_name)
-                .unwrap_or_else(|| panic!("file `{}` missing in archive", e_file_name.display()));
-            assert_match_exact(e_file_contents, actual_contents);
-        }
-    }
+    actual_contents.assert_contains(&expected_contents);
 }
 
 pub(crate) fn create_index_line(
diff --git a/tests/testsuite/artifact_dep.rs b/tests/testsuite/artifact_dep.rs
index 80ff28bab5c..7360992459b 100644
--- a/tests/testsuite/artifact_dep.rs
+++ b/tests/testsuite/artifact_dep.rs
@@ -2339,10 +2339,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "foo-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "foo"
@@ -2378,9 +2388,9 @@ artifact = [
     "cdylib",
     "staticlib",
 ]
-target = "target""#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+target = "target"
+
+"##]],
         )],
     );
 }
diff --git a/tests/testsuite/cross_publish.rs b/tests/testsuite/cross_publish.rs
index 2646dea4083..fa74669b482 100644
--- a/tests/testsuite/cross_publish.rs
+++ b/tests/testsuite/cross_publish.rs
@@ -58,7 +58,7 @@ fn simple_cross_package() {
         f,
         "foo-0.0.0.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[],
+        (),
     );
 }
 
diff --git a/tests/testsuite/features2.rs b/tests/testsuite/features2.rs
index 8f469e2b110..c8142b7d8a2 100644
--- a/tests/testsuite/features2.rs
+++ b/tests/testsuite/features2.rs
@@ -1788,8 +1788,18 @@ fn package_includes_resolve_behavior() {
 
     p.cargo("package").cwd("a").run();
 
-    let rewritten_toml = format!(
-        r#"{}
+    let rewritten_toml = str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "a"
@@ -1810,16 +1820,15 @@ resolver = "2"
 [lib]
 name = "a"
 path = "src/lib.rs"
-"#,
-        cargo::core::manifest::MANIFEST_PREAMBLE
-    );
+
+"##]];
 
     let f = File::open(&p.root().join("target/package/a-0.1.0.crate")).unwrap();
     validate_crate_contents(
         f,
         "a-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[("Cargo.toml", &rewritten_toml)],
+        [("Cargo.toml", rewritten_toml)],
     );
 }
 
diff --git a/tests/testsuite/features_namespaced.rs b/tests/testsuite/features_namespaced.rs
index a620f441b69..7712bf7d5ef 100644
--- a/tests/testsuite/features_namespaced.rs
+++ b/tests/testsuite/features_namespaced.rs
@@ -976,10 +976,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "foo-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "foo"
@@ -1009,9 +1019,8 @@ optional = true
 
 [features]
 feat = ["opt-dep1"]
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
@@ -1104,10 +1113,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "foo-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "foo"
@@ -1135,9 +1154,8 @@ optional = true
 feat1 = []
 feat2 = ["dep:bar"]
 feat3 = ["feat2"]
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
diff --git a/tests/testsuite/inheritable_workspace_fields.rs b/tests/testsuite/inheritable_workspace_fields.rs
index 8af4724a8aa..7ac3252eb2e 100644
--- a/tests/testsuite/inheritable_workspace_fields.rs
+++ b/tests/testsuite/inheritable_workspace_fields.rs
@@ -206,10 +206,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
             ".cargo_vcs_info.json",
             "bar.txt",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2018"
 rust-version = "1.60"
@@ -241,9 +251,8 @@ repository = "https://github.com/example/example"
 [[bin]]
 name = "foo"
 path = "src/main.rs"
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
@@ -385,10 +394,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "bar-0.2.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "Cargo.lock", "src/main.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "bar"
@@ -414,9 +433,8 @@ version = "0.5.2"
 
 [build-dependencies.dep-build]
 version = "0.8"
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
@@ -525,10 +543,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "bar-0.2.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "Cargo.lock", "src/main.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "bar"
@@ -549,9 +577,8 @@ path = "src/main.rs"
 [dependencies.dep]
 version = "0.1.2"
 features = ["testing"]
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
@@ -776,10 +803,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
             ".cargo_vcs_info.json",
             "bar.txt",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2018"
 rust-version = "1.60"
@@ -814,9 +851,8 @@ repository = "https://github.com/example/example"
 [[bin]]
 name = "bar"
 path = "src/main.rs"
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
@@ -960,10 +996,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "bar-0.2.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "Cargo.lock", "src/main.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "bar"
@@ -989,9 +1035,8 @@ version = "0.5.2"
 
 [build-dependencies.dep-build]
 version = "0.8"
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
diff --git a/tests/testsuite/package.rs b/tests/testsuite/package.rs
index 046635a0534..3984d5dae4f 100644
--- a/tests/testsuite/package.rs
+++ b/tests/testsuite/package.rs
@@ -73,7 +73,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[],
+        (),
     );
 }
 
@@ -183,8 +183,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
     "sha1": "{}"
   }},
   "path_in_vcs": ""
-}}
-"#,
+}}"#,
         repo.revparse_head()
     );
     validate_crate_contents(
@@ -197,7 +196,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
             "src/main.rs",
             ".cargo_vcs_info.json",
         ],
-        &[(".cargo_vcs_info.json", &vcs_contents)],
+        [(".cargo_vcs_info.json", &vcs_contents)],
     );
 
     println!("package sub-repo");
@@ -223,8 +222,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
     "sha1": "{}"
   }},
   "path_in_vcs": "a/a"
-}}
-"#,
+}}"#,
         repo.revparse_head()
     );
     validate_crate_contents(
@@ -236,7 +234,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
             "src/lib.rs",
             ".cargo_vcs_info.json",
         ],
-        &[(".cargo_vcs_info.json", &vcs_contents)],
+        [(".cargo_vcs_info.json", &vcs_contents)],
     );
 }
 
@@ -757,7 +755,7 @@ src/main.rs
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[],
+        (),
     );
 }
 
@@ -818,7 +816,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
             "src/main.rs",
             "src/foo.rs",
         ],
-        &[],
+        (),
     );
 }
 
@@ -1185,15 +1183,18 @@ fn issue_13695_allow_dirty_vcs_info() {
             "Cargo.toml.orig",
             "src/lib.rs",
         ],
-        &[(
+        [(
             ".cargo_vcs_info.json",
-            r#"{
+            str![[r#"
+{
   "git": {
-    "sha1": "[..]",
-    "dirty": true
+    "dirty": true,
+    "sha1": "[..]"
   },
   "path_in_vcs": ""
-}"#,
+}
+"#]]
+            .is_json(),
         )],
     );
 
@@ -1242,14 +1243,17 @@ fn issue_13695_allowing_dirty_vcs_info_but_clean() {
             "Cargo.toml.orig",
             "src/lib.rs",
         ],
-        &[(
+        [(
             ".cargo_vcs_info.json",
-            r#"{
+            str![[r#"
+{
   "git": {
     "sha1": "[..]"
   },
   "path_in_vcs": ""
-}"#,
+}
+"#]]
+            .is_json(),
         )],
     );
 }
@@ -1280,13 +1284,13 @@ fn issue_14354_allowing_dirty_bare_commit() {
         f,
         "foo-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[],
+        (),
     );
 }
 
 #[cargo_test]
 fn generated_manifest() {
-    let registry = registry::alt_init();
+    registry::alt_init();
     Package::new("abc", "1.0.0").publish();
     Package::new("def", "1.0.0").alternative(true).publish();
     Package::new("ghi", "1.0.0").publish();
@@ -1325,8 +1329,18 @@ fn generated_manifest() {
     p.cargo("package --no-verify").run();
 
     let f = File::open(&p.root().join("target/package/foo-0.0.1.crate")).unwrap();
-    let rewritten_toml = format!(
-        r#"{}
+    let rewritten_toml = str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "foo"
@@ -1358,20 +1372,18 @@ version = "0.1"
 
 [dependencies.def]
 version = "1.0"
-registry-index = "{}"
+registry-index = "[ROOTURL]/alternative-registry"
 
 [dependencies.ghi]
 version = "1.0"
-"#,
-        cargo::core::manifest::MANIFEST_PREAMBLE,
-        registry.index_url()
-    );
+
+"##]];
 
     validate_crate_contents(
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[("Cargo.toml", &rewritten_toml)],
+        [("Cargo.toml", rewritten_toml)],
     );
 }
 
@@ -1412,8 +1424,18 @@ fn ignore_workspace_specifier() {
     p.cargo("package --no-verify").cwd("bar").run();
 
     let f = File::open(&p.root().join("target/package/bar-0.1.0.crate")).unwrap();
-    let rewritten_toml = format!(
-        r#"{}
+    let rewritten_toml = str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "bar"
@@ -1430,14 +1452,13 @@ readme = false
 [lib]
 name = "bar"
 path = "src/lib.rs"
-"#,
-        cargo::core::manifest::MANIFEST_PREAMBLE
-    );
+
+"##]];
     validate_crate_contents(
         f,
         "bar-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[("Cargo.toml", &rewritten_toml)],
+        [("Cargo.toml", rewritten_toml)],
     );
 }
 
@@ -1491,8 +1512,18 @@ fn package_public_dep() {
         )
         .file("src/main.rs", "fn main() {}")
         .build();
-    let rewritten_toml = format!(
-        r#"{}
+    let rewritten_toml = str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "foo"
@@ -1512,16 +1543,24 @@ path = "src/main.rs"
 [dependencies.bar]
 version = "1.0.0"
 
-[target.{host}.dependencies.baz]
+[target.[HOST_TARGET].dependencies.baz]
 version = "1.0.0"
-"#,
-        cargo::core::manifest::MANIFEST_PREAMBLE,
-        host = rustc_host()
-    );
+
+"##]];
     verify(&p, "package", rewritten_toml);
 
-    let rewritten_toml = format!(
-        r#"{}
+    let rewritten_toml = str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "foo"
@@ -1542,16 +1581,14 @@ path = "src/main.rs"
 version = "1.0.0"
 public = true
 
-[target.{host}.dependencies.baz]
+[target.[HOST_TARGET].dependencies.baz]
 version = "1.0.0"
 public = true
-"#,
-        cargo::core::manifest::MANIFEST_PREAMBLE,
-        host = rustc_host()
-    );
+
+"##]];
     verify(&p, "package -Zpublic-dependency", rewritten_toml);
 
-    fn verify(p: &cargo_test_support::Project, cmd: &str, rewritten_toml: String) {
+    fn verify(p: &cargo_test_support::Project, cmd: &str, rewritten_toml: impl IntoData) {
         p.cargo(cmd)
             .masquerade_as_nightly_cargo(&["public-dependency"])
             .run();
@@ -1560,7 +1597,7 @@ public = true
             f,
             "foo-0.0.1.crate",
             &["Cargo.toml", "Cargo.toml.orig", "Cargo.lock", "src/main.rs"],
-            &[("Cargo.toml", &rewritten_toml)],
+            [("Cargo.toml", rewritten_toml)],
         );
     }
 }
@@ -2274,7 +2311,7 @@ subdir/LICENSE
             "subdir/LICENSE",
             "src/lib.rs",
         ],
-        &[("subdir/LICENSE", "license text")],
+        [("subdir/LICENSE", "license text")],
     );
 }
 
@@ -2324,7 +2361,7 @@ src/lib.rs
         f,
         "foo-1.0.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "LICENSE", "src/lib.rs"],
-        &[("LICENSE", "license text")],
+        [("LICENSE", "license text")],
     );
     let manifest =
         std::fs::read_to_string(p.root().join("target/package/foo-1.0.0/Cargo.toml")).unwrap();
@@ -2383,7 +2420,7 @@ src/lib.rs
         f,
         "foo-1.0.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "LICENSE", "src/lib.rs"],
-        &[("LICENSE", "inner license")],
+        [("LICENSE", "inner license")],
     );
     let manifest = read_to_string(p.root().join("target/package/foo-1.0.0/Cargo.toml")).unwrap();
     assert!(manifest.contains("license-file = \"LICENSE\""));
@@ -2983,8 +3020,18 @@ fn workspace_overrides_resolver() {
     p.cargo("package --no-verify -p bar -p baz").run();
 
     let f = File::open(&p.root().join("target/package/bar-0.1.0.crate")).unwrap();
-    let rewritten_toml = format!(
-        r#"{}
+    let rewritten_toml = str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2021"
 name = "bar"
@@ -3001,20 +3048,29 @@ resolver = "1"
 [lib]
 name = "bar"
 path = "src/lib.rs"
-"#,
-        cargo::core::manifest::MANIFEST_PREAMBLE
-    );
+
+"##]];
     validate_crate_contents(
         f,
         "bar-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[("Cargo.toml", &rewritten_toml)],
+        [("Cargo.toml", rewritten_toml)],
     );
 
     // When the crate has the same implicit resolver as the workspace it is not overridden
     let f = File::open(&p.root().join("target/package/baz-0.1.0.crate")).unwrap();
-    let rewritten_toml = format!(
-        r#"{}
+    let rewritten_toml = str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "baz"
@@ -3030,14 +3086,13 @@ readme = false
 [lib]
 name = "baz"
 path = "src/lib.rs"
-"#,
-        cargo::core::manifest::MANIFEST_PREAMBLE
-    );
+
+"##]];
     validate_crate_contents(
         f,
         "baz-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[("Cargo.toml", &rewritten_toml)],
+        [("Cargo.toml", rewritten_toml)],
     );
 }
 
@@ -3157,7 +3212,7 @@ src/main.rs
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[
+        [
             ("Cargo.lock", cargo_lock_contents),
             ("Cargo.toml", &cargo_toml_contents),
             ("Cargo.toml.orig", cargo_toml_orig_contents),
@@ -3268,7 +3323,7 @@ src/main.rs
             "src/bar.txt",
             "src/main.rs",
         ],
-        &[
+        [
             ("Cargo.lock", cargo_lock_contents),
             ("Cargo.toml", &cargo_toml_contents),
             ("Cargo.toml.orig", cargo_toml_orig_contents),
@@ -3391,7 +3446,7 @@ src/main.rs.bak
             "src/main.rs",
             "src/main.rs.bak",
         ],
-        &[
+        [
             ("Cargo.lock", cargo_lock_contents),
             ("Cargo.toml", &cargo_toml_contents),
             ("Cargo.toml.orig", cargo_toml_orig_contents),
@@ -3494,10 +3549,20 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
             "Examples/ExampleFoo.rs",
             "Tests/ExplicitPath.rs",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2018"
 name = "foo"
@@ -3517,9 +3582,8 @@ license = "MIT"
 [lib]
 name = "foo"
 path = "src/lib.rs"
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
@@ -3584,7 +3648,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[],
+        (),
     );
 }
 
@@ -3621,7 +3685,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
         f,
         "foo-0.0.0.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[],
+        (),
     );
 }
 
@@ -3893,9 +3957,10 @@ fn normalize_paths() {
             "tests/test_foo.rs",
             "benches/bench_foo.rs",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -3941,7 +4006,8 @@ path = "tests/test_foo.rs"
 [[bench]]
 name = "bench_foo"
 path = "benches/bench_foo.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -3984,9 +4050,10 @@ fn discovery_inferred_build_rs_included() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs", "build.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4020,7 +4087,8 @@ license = "MIT"
 [lib]
 name = "foo"
 path = "src/lib.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4064,9 +4132,10 @@ fn discovery_inferred_build_rs_excluded() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4097,7 +4166,8 @@ license = "MIT"
 [lib]
 name = "foo"
 path = "src/lib.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4141,9 +4211,10 @@ fn discovery_explicit_build_rs_included() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs", "build.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4177,7 +4248,8 @@ license = "MIT"
 [lib]
 name = "foo"
 path = "src/lib.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4222,9 +4294,10 @@ fn discovery_explicit_build_rs_excluded() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4255,7 +4328,8 @@ license = "MIT"
 [lib]
 name = "foo"
 path = "src/lib.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4304,9 +4378,10 @@ fn discovery_inferred_lib_included() {
             "src/main.rs",
             "src/lib.rs",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4344,7 +4419,8 @@ path = "src/lib.rs"
 [[bin]]
 name = "foo"
 path = "src/main.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4388,9 +4464,10 @@ fn discovery_inferred_lib_excluded() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4421,7 +4498,8 @@ license = "MIT"
 [[bin]]
 name = "foo"
 path = "src/main.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4473,9 +4551,10 @@ fn discovery_explicit_lib_included() {
             "src/main.rs",
             "src/lib.rs",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4513,7 +4592,8 @@ path = "src/lib.rs"
 [[bin]]
 name = "foo"
 path = "src/main.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4560,9 +4640,10 @@ fn discovery_explicit_lib_excluded() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4593,7 +4674,8 @@ license = "MIT"
 [[bin]]
 name = "foo"
 path = "src/main.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4648,9 +4730,10 @@ fn discovery_inferred_other_included() {
             "tests/test_foo.rs",
             "benches/bench_foo.rs",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4703,7 +4786,8 @@ path = "tests/test_foo.rs"
 [[bench]]
 name = "bench_foo"
 path = "benches/bench_foo.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4753,9 +4837,10 @@ fn discovery_inferred_other_excluded() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4786,7 +4871,8 @@ license = "MIT"
 [lib]
 name = "foo"
 path = "src/lib.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4853,9 +4939,10 @@ fn discovery_explicit_other_included() {
             "tests/test_foo.rs",
             "benches/bench_foo.rs",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -4908,7 +4995,8 @@ path = "tests/test_foo.rs"
 [[bench]]
 name = "bench_foo"
 path = "benches/bench_foo.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -4970,9 +5058,10 @@ fn discovery_explicit_other_excluded() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -5003,7 +5092,8 @@ license = "MIT"
 [lib]
 name = "foo"
 path = "src/lib.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -5070,9 +5160,10 @@ fn deterministic_build_targets() {
             "examples/y.rs",
             "examples/z.rs",
         ],
-        &[(
+        [(
             "Cargo.toml",
-            r#"# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
 #
 # When uploading crates to the registry Cargo will automatically
 # "normalize" Cargo.toml files for maximal compatibility
@@ -5126,7 +5217,8 @@ path = "examples/y.rs"
 [[example]]
 name = "z"
 path = "examples/z.rs"
-"#,
+
+"##]],
         )],
     );
 }
@@ -5262,8 +5354,8 @@ fn workspace_with_local_deps_nightly() {
 "#]])
         .run();
 
-    let generated_lock = format!(
-        r#"# This file is automatically @generated by Cargo.
+    let generated_lock = str![[r##"
+# This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
 version = 4
 
@@ -5278,7 +5370,7 @@ dependencies = [
 name = "level2"
 version = "0.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = [..]
+checksum = "[..]"
 dependencies = [
  "level3",
 ]
@@ -5287,12 +5379,22 @@ dependencies = [
 name = "level3"
 version = "0.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = [..]
-"#
-    );
+checksum = "[..]"
+
+"##]];
+
+    let generated_manifest = str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
 
-    let generated_manifest = format!(
-        r#"{}
 [package]
 edition = "2015"
 name = "level1"
@@ -5316,9 +5418,8 @@ path = "src/main.rs"
 [dependencies.level2]
 version = "0.0.1"
 features = ["foo"]
-"#,
-        cargo::core::manifest::MANIFEST_PREAMBLE,
-    );
+
+"##]];
 
     let mut f = File::open(&p.root().join("target/package/level1-0.0.1.crate")).unwrap();
 
@@ -5326,9 +5427,9 @@ features = ["foo"]
         &mut f,
         "level1-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[
-            ("Cargo.lock", &generated_lock),
-            ("Cargo.toml", &generated_manifest),
+        [
+            ("Cargo.lock", generated_lock),
+            ("Cargo.toml", generated_manifest),
         ],
     );
 }
@@ -5805,7 +5906,7 @@ dependencies = [
 name = "level2"
 version = "0.0.1"
 source = "{index}"
-checksum = [..]
+checksum = "[..]"
 "#
     );
 
@@ -5815,7 +5916,7 @@ checksum = [..]
         &mut f,
         "level1-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[("Cargo.lock", &generated_lock)],
+        [("Cargo.lock", generated_lock)],
     );
 }
 
diff --git a/tests/testsuite/publish.rs b/tests/testsuite/publish.rs
index 82b689e034e..eb1292110ae 100644
--- a/tests/testsuite/publish.rs
+++ b/tests/testsuite/publish.rs
@@ -1571,57 +1571,68 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "foo-0.1.0.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[
+        [
             (
                 "Cargo.toml",
                 // Check that only `version` is included in Cargo.toml.
-                &format!(
-                    "{}\n\
-                     [package]\n\
-                     edition = \"2018\"\n\
-                     name = \"foo\"\n\
-                     version = \"0.1.0\"\n\
-                     authors = []\n\
-                     build = false\n\
-                     autolib = false\n\
-                     autobins = false\n\
-                     autoexamples = false\n\
-                     autotests = false\n\
-                     autobenches = false\n\
-                     description = \"foo\"\n\
-                     readme = false\n\
-                     license = \"MIT\"\n\
-                     \n\
-                     [[bin]]\n\
-                     name = \"foo\"\n\
-                     path = \"src/main.rs\"\n\
-                     \n\
-                     [dependencies.dep1]\n\
-                     version = \"1.0\"\n\
-                    ",
-                    cargo::core::manifest::MANIFEST_PREAMBLE
-                ),
+                str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
+[package]
+edition = "2018"
+name = "foo"
+version = "0.1.0"
+authors = []
+build = false
+autolib = false
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+description = "foo"
+readme = false
+license = "MIT"
+
+[[bin]]
+name = "foo"
+path = "src/main.rs"
+
+[dependencies.dep1]
+version = "1.0"
+
+"##]],
             ),
             (
                 "Cargo.lock",
                 // The important check here is that it is 1.0.1 in the registry.
-                "# This file is automatically @generated by Cargo.\n\
-                 # It is not intended for manual editing.\n\
-                 version = 4\n\
-                 \n\
-                 [[package]]\n\
-                 name = \"dep1\"\n\
-                 version = \"1.0.1\"\n\
-                 source = \"registry+https://github.com/rust-lang/crates.io-index\"\n\
-                 checksum = \"[..]\"\n\
-                 \n\
-                 [[package]]\n\
-                 name = \"foo\"\n\
-                 version = \"0.1.0\"\n\
-                 dependencies = [\n\
-                 \x20\"dep1\",\n\
-                 ]\n\
-                 ",
+                str![[r##"
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "dep1"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "[..]"
+
+[[package]]
+name = "foo"
+version = "0.1.0"
+dependencies = [
+ "dep1",
+]
+
+"##]],
             ),
         ],
     );
@@ -1954,10 +1965,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "foo-0.1.0.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[(
-            "Cargo.toml",
-            &format!(
-                r#"{}
+        [(
+            "Cargo.toml",
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "foo"
@@ -2047,9 +2068,8 @@ features = ["cat"]
 [target."cfg(unix)".dev-dependencies.target-normal-and-dev]
 version = "1.0"
 features = ["cat"]
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }
diff --git a/tests/testsuite/publish_lockfile.rs b/tests/testsuite/publish_lockfile.rs
index 059d6ce54d6..0ba0e6e6f8d 100644
--- a/tests/testsuite/publish_lockfile.rs
+++ b/tests/testsuite/publish_lockfile.rs
@@ -108,7 +108,7 @@ src/main.rs
         f,
         "foo-0.0.1.crate",
         &["Cargo.toml", "Cargo.toml.orig", "Cargo.lock", "src/main.rs"],
-        &[],
+        (),
     );
 }
 
@@ -163,7 +163,7 @@ fn no_lock_file_with_library() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[],
+        (),
     );
 }
 
@@ -188,7 +188,7 @@ fn lock_file_and_workspace() {
         f,
         "foo-0.0.1.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/main.rs", "Cargo.lock"],
-        &[],
+        (),
     );
 }
 
@@ -576,7 +576,7 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
         f,
         "foo-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[],
+        (),
     );
 
     let package_path = p.root().join("target/package/bar-0.0.1.crate");
@@ -586,6 +586,6 @@ See https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata for
         f,
         "bar-0.0.1.crate",
         &["Cargo.lock", "Cargo.toml", "Cargo.toml.orig", "src/main.rs"],
-        &[],
+        (),
     );
 }
diff --git a/tests/testsuite/weak_dep_features.rs b/tests/testsuite/weak_dep_features.rs
index 3e931be3a6f..b26d767de94 100644
--- a/tests/testsuite/weak_dep_features.rs
+++ b/tests/testsuite/weak_dep_features.rs
@@ -621,10 +621,20 @@ You may press ctrl-c to skip waiting; the crate should be available shortly.
         "#,
         "foo-0.1.0.crate",
         &["Cargo.toml", "Cargo.toml.orig", "src/lib.rs"],
-        &[(
+        [(
             "Cargo.toml",
-            &format!(
-                r#"{}
+            str![[r##"
+# THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
+#
+# When uploading crates to the registry Cargo will automatically
+# "normalize" Cargo.toml files for maximal compatibility
+# with all versions of Cargo and also rewrite `path` dependencies
+# to registry (e.g., crates.io) dependencies.
+#
+# If you are reading this file be aware that the original Cargo.toml
+# will likely look very different (and much more reasonable).
+# See Cargo.toml.orig for the original contents.
+
 [package]
 edition = "2015"
 name = "foo"
@@ -651,9 +661,8 @@ optional = true
 [features]
 feat1 = []
 feat2 = ["bar?/feat"]
-"#,
-                cargo::core::manifest::MANIFEST_PREAMBLE
-            ),
+
+"##]],
         )],
     );
 }