Unify handling of file & inline snapshots

This is the code for mitsuhiko#456 (comment), as mentioned in mitsuhiko#466.

There's a very small change in yaml inline snapshots — shown here in the tests. In return, it makes the macros simpler & more maintainable.

Author: max-sixty

src/macros.rs

@@ -223,59 +223,39 @@ macro_rules! assert_compact_json_snapshot {
 #[doc(hidden)]
 #[macro_export]
 macro_rules! _assert_serialized_snapshot {
-    // If there are redaction expressions and an inline snapshot, capture
-    // the redactions expressions and pass to `_assert_snapshot_base`
-    //
-    // Note that if we could unify the Inline & File represenations of snapshots
-    // redactions we could unify some of these branches.
-
-    (format=$format:ident, $value:expr, $(match ..)? {$($k:expr => $v:expr),* $(,)?}, @$snapshot:literal) => {{
+    // If there are redaction expressions, capture the redactions expressions
+    // and pass to `_assert_snapshot_base`
+    (format=$format:ident, $value:expr, $(match ..)? {$($k:expr => $v:expr),* $(,)?} $($arg:tt)*) => {{
         let transform = |value| {
-            let (_, value) = $crate::_prepare_snapshot_for_redaction!(value, {$($k => $v),*}, $format, Inline);
+            let (_, value) = $crate::_prepare_snapshot_for_redaction!(value, {$($k => $v),*}, $format);
             value
         };
-        $crate::_assert_snapshot_base!(transform=transform, $value, @$snapshot);
+        $crate::_assert_snapshot_base!(transform=transform, $value $($arg)*);
     }};
-    // If there are redaction expressions and no name, add a auto-generated name, call self
-    (format=$format:ident, $value:expr, $(match ..)? {$($k:expr => $v:expr),* $(,)?} $(,)?) => {{
-        $crate::_assert_serialized_snapshot!(format=$format, $crate::_macro_support::AutoName, $value, {$($k => $v),*});
-    }};
-    // If there are redaction expressions, capture and pass to `_assert_snapshot_base`
+    // If there's a name and redaction expressions, capture and pass to `_assert_snapshot_base`
     (format=$format:ident, $name:expr, $value:expr, $(match ..)? {$($k:expr => $v:expr),* $(,)?} $(,)?) => {{
         let transform = |value| {
-            let (_, value) = $crate::_prepare_snapshot_for_redaction!(value, {$($k => $v),*}, $format, File);
+            let (_, value) = $crate::_prepare_snapshot_for_redaction!(value, {$($k => $v),*}, $format);
             value
         };
         $crate::_assert_snapshot_base!(transform=transform, $name, $value);
     }};
-    // If there's an inline snapshot, capture serialization function and pass to
-    // `_assert_snapshot_base`, specifying `Inline`
+    // Capture serialization function and pass to `_assert_snapshot_base`
     //
-    (format=$format:ident, $($arg:expr),*, @$snapshot:literal) => {{
-        let transform = |value| {$crate::_macro_support::serialize_value(
-            &value,
-            $crate::_macro_support::SerializationFormat::$format,
-            $crate::_macro_support::SnapshotLocation::Inline
-        )};
-        $crate::_assert_snapshot_base!(transform = transform, $($arg),*, @$snapshot);
-    }};
-    // Capture serialization function and pass to `_assert_snapshot_base`,
-    // specifying `File`
-    (format=$format:ident, $($arg:expr),* $(,)?) => {{
+    (format=$format:ident, $($arg:tt)*) => {{
         let transform = |value| {$crate::_macro_support::serialize_value(
             &value,
             $crate::_macro_support::SerializationFormat::$format,
-            $crate::_macro_support::SnapshotLocation::File
         )};
-        $crate::_assert_snapshot_base!(transform = transform, $($arg),*);
+        $crate::_assert_snapshot_base!(transform = transform, $($arg)*);
     }};
 }
 
 #[cfg(feature = "redactions")]
 #[doc(hidden)]
 #[macro_export]
 macro_rules! _prepare_snapshot_for_redaction {
-    ($value:expr, {$($k:expr => $v:expr),*}, $format:ident, $location:ident) => {
+    ($value:expr, {$($k:expr => $v:expr),*}, $format:ident) => {
         {
             let vec = vec![
                 $((
@@ -287,7 +267,6 @@ macro_rules! _prepare_snapshot_for_redaction {
                 &$value,
                 &vec,
                 $crate::_macro_support::SerializationFormat::$format,
-                $crate::_macro_support::SnapshotLocation::$location
             );
             (vec, value)
         }
@@ -298,7 +277,7 @@ macro_rules! _prepare_snapshot_for_redaction {
 #[doc(hidden)]
 #[macro_export]
 macro_rules! _prepare_snapshot_for_redaction {
-    ($value:expr, {$($k:expr => $v:expr),*}, $format:ident, $location:ident) => {
+    ($value:expr, {$($k:expr => $v:expr),*}, $format:ident) => {
         compile_error!("insta was compiled without redaction support.");
     };
 }

src/serialization.rs

@@ -22,11 +22,7 @@ pub enum SnapshotLocation {
     File,
 }
 
-pub fn serialize_content(
-    mut content: Content,
-    format: SerializationFormat,
-    location: SnapshotLocation,
-) -> String {
+pub fn serialize_content(mut content: Content, format: SerializationFormat) -> String {
     content = Settings::with(|settings| {
         if settings.sort_maps() {
             content.sort_maps();
@@ -41,13 +37,7 @@ pub fn serialize_content(
     });
 
     match format {
-        SerializationFormat::Yaml => {
-            let serialized = yaml::to_string(&content);
-            match location {
-                SnapshotLocation::Inline => serialized,
-                SnapshotLocation::File => serialized[4..].to_string(),
-            }
-        }
+        SerializationFormat::Yaml => yaml::to_string(&content)[4..].to_string(),
         SerializationFormat::Json => json::to_string_pretty(&content),
         SerializationFormat::JsonCompact => json::to_string_compact(&content),
         #[cfg(feature = "csv")]
@@ -98,29 +88,24 @@ pub fn serialize_content(
     }
 }
 
-pub fn serialize_value<S: Serialize>(
-    s: &S,
-    format: SerializationFormat,
-    location: SnapshotLocation,
-) -> String {
+pub fn serialize_value<S: Serialize>(s: &S, format: SerializationFormat) -> String {
     let serializer = ContentSerializer::<ValueError>::new();
     let content = Serialize::serialize(s, serializer).unwrap();
-    serialize_content(content, format, location)
+    serialize_content(content, format)
 }
 
 #[cfg(feature = "redactions")]
 pub fn serialize_value_redacted<S: Serialize>(
     s: &S,
     redactions: &[(crate::redaction::Selector, crate::redaction::Redaction)],
     format: SerializationFormat,
-    location: SnapshotLocation,
 ) -> String {
     let serializer = ContentSerializer::<ValueError>::new();
     let mut content = Serialize::serialize(s, serializer).unwrap();
     for (selector, redaction) in redactions {
         content = selector.redact(content, redaction);
     }
-    serialize_content(content, format, location)
+    serialize_content(content, format)
 }
 
 #[test]
@@ -140,7 +125,6 @@ fn test_yaml_serialization() {
             ),
         ]),
         SerializationFormat::Yaml,
-        SnapshotLocation::File,
     );
     crate::assert_snapshot!(&yaml, @r###"
     env:
@@ -166,10 +150,8 @@ fn test_yaml_serialization() {
             ),
         ]),
         SerializationFormat::Yaml,
-        SnapshotLocation::Inline,
     );
     crate::assert_snapshot!(&inline_yaml, @r###"
-    ---
     env:
       - ENVIRONMENT
       - production

tests/test_inline.rs

@@ -183,7 +183,6 @@ fn test_yaml_inline() {
         username: "peter-pan".into(),
         email: "peterpan@wonderland.invalid".into()
     }, @r###"
-    ---
     id: 42
     username: peter-pan
     email: peterpan@wonderland.invalid
@@ -207,7 +206,6 @@ fn test_yaml_inline_redacted() {
     }, {
         ".id" => "[user-id]"
     }, @r###"
-    ---
     id: "[user-id]"
     username: peter-pan
     email: peterpan@wonderland.invalid

tests/test_redaction.rs

@@ -331,7 +331,6 @@ fn test_redact_newtype_enum() {
     assert_yaml_snapshot!(visitor, {
         r#".id"# => "[id]",
     }, @r###"
-    ---
     Visitor:
       id: "[id]"
       name: my-name
@@ -346,7 +345,6 @@ fn test_redact_newtype_enum() {
     assert_yaml_snapshot!(admin, {
         r#".id"# => "[id]",
     }, @r###"
-    ---
     Admin:
       id: "[id]"
       username: john_doe

tests/test_settings.rs

@@ -17,7 +17,6 @@ fn test_simple() {
     settings.set_sort_maps(true);
     settings.bind(|| {
         assert_yaml_snapshot!(&map, @r###"
-        ---
         a: first value
         b: second value
         c: third value
@@ -40,7 +39,6 @@ fn test_bound_to_scope() {
         settings.set_sort_maps(true);
         let _guard = settings.bind_to_scope();
         assert_yaml_snapshot!(&map, @r###"
-        ---
         a: first value
         b: second value
         c: third value
@@ -62,7 +60,6 @@ fn test_settings_macro() {
 
     with_settings!({sort_maps => true}, {
         insta::assert_yaml_snapshot!(&map, @r###"
-        ---
         a: first value
         b: second value
         c: third value