Merge remote-tracking branch 'origin/main' into dcreager/smoosh-reachability

* origin/main:
  [ty] Expansion of enums into unions of literals (#19382)
  [ty] Avoid rechecking the entire project when changing the opened files (#19463)
  [ty] Add warning for unknown `TY_MEMORY_REPORT` value (#19465)

Author: dcreager

crates/ty/src/lib.rs

@@ -156,7 +156,12 @@ fn run_check(args: CheckCommand) -> anyhow::Result<ExitStatus> {
         Ok("short") => write!(stdout, "{}", db.salsa_memory_dump().display_short())?,
         Ok("mypy_primer") => write!(stdout, "{}", db.salsa_memory_dump().display_mypy_primer())?,
         Ok("full") => write!(stdout, "{}", db.salsa_memory_dump().display_full())?,
-        _ => {}
+        Ok(other) => {
+            tracing::warn!(
+                "Unknown value for `TY_MEMORY_REPORT`: `{other}`. Valid values are `short`, `mypy_primer`, and `full`."
+            );
+        }
+        Err(_) => {}
     }
 
     std::mem::forget(db);

crates/ty_project/src/lib.rs

@@ -252,6 +252,7 @@ impl Project {
                 .map(IOErrorDiagnostic::to_diagnostic),
         );
 
+        let open_files = self.open_files(db);
         let check_start = ruff_db::Instant::now();
         let file_diagnostics = std::sync::Mutex::new(vec![]);
 
@@ -269,11 +270,30 @@ impl Project {
                             tracing::debug_span!(parent: project_span, "check_file", ?file);
                         let _entered = check_file_span.entered();
 
-                        let result = check_file_impl(&db, file);
-                        file_diagnostics
-                            .lock()
-                            .unwrap()
-                            .extend(result.iter().map(Clone::clone));
+                        match check_file_impl(&db, file) {
+                            Ok(diagnostics) => {
+                                file_diagnostics
+                                    .lock()
+                                    .unwrap()
+                                    .extend(diagnostics.iter().map(Clone::clone));
+
+                                // This is outside `check_file_impl` to avoid that opening or closing
+                                // a file invalidates the `check_file_impl` query of every file!
+                                if !open_files.contains(&file) {
+                                    // The module has already been parsed by `check_file_impl`.
+                                    // We only retrieve it here so that we can call `clear` on it.
+                                    let parsed = parsed_module(&db, file);
+
+                                    // Drop the AST now that we are done checking this file. It is not currently open,
+                                    // so it is unlikely to be accessed again soon. If any queries need to access the AST
+                                    // from across files, it will be re-parsed.
+                                    parsed.clear();
+                                }
+                            }
+                            Err(io_error) => {
+                                file_diagnostics.lock().unwrap().push(io_error.clone());
+                            }
+                        }
 
                         reporter.report_file(&file);
                     });
@@ -300,7 +320,10 @@ impl Project {
             return Vec::new();
         }
 
-        check_file_impl(db, file).iter().map(Clone::clone).collect()
+        match check_file_impl(db, file) {
+            Ok(diagnostics) => diagnostics.to_vec(),
+            Err(diagnostic) => vec![diagnostic.clone()],
+        }
     }
 
     /// Opens a file in the project.
@@ -484,22 +507,19 @@ impl Project {
     }
 }
 
-#[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]
-pub(crate) fn check_file_impl(db: &dyn Db, file: File) -> Box<[Diagnostic]> {
+#[salsa::tracked(returns(ref), heap_size=get_size2::GetSize::get_heap_size)]
+pub(crate) fn check_file_impl(db: &dyn Db, file: File) -> Result<Box<[Diagnostic]>, Diagnostic> {
     let mut diagnostics: Vec<Diagnostic> = Vec::new();
 
     // Abort checking if there are IO errors.
     let source = source_text(db, file);
 
     if let Some(read_error) = source.read_error() {
-        diagnostics.push(
-            IOErrorDiagnostic {
-                file: Some(file),
-                error: read_error.clone().into(),
-            }
-            .to_diagnostic(),
-        );
-        return diagnostics.into_boxed_slice();
+        return Err(IOErrorDiagnostic {
+            file: Some(file),
+            error: read_error.clone().into(),
+        }
+        .to_diagnostic());
     }
 
     let parsed = parsed_module(db, file);
@@ -529,13 +549,6 @@ pub(crate) fn check_file_impl(db: &dyn Db, file: File) -> Box<[Diagnostic]> {
         }
     }
 
-    if !db.project().open_fileset(db).contains(&file) {
-        // Drop the AST now that we are done checking this file. It is not currently open,
-        // so it is unlikely to be accessed again soon. If any queries need to access the AST
-        // from across files, it will be re-parsed.
-        parsed.clear();
-    }
-
     diagnostics.sort_unstable_by_key(|diagnostic| {
         diagnostic
             .primary_span()
@@ -544,7 +557,7 @@ pub(crate) fn check_file_impl(db: &dyn Db, file: File) -> Box<[Diagnostic]> {
             .start()
     });
 
-    diagnostics.into_boxed_slice()
+    Ok(diagnostics.into_boxed_slice())
 }
 
 #[derive(Debug)]
@@ -762,10 +775,11 @@ mod tests {
         assert_eq!(source_text(&db, file).as_str(), "");
         assert_eq!(
             check_file_impl(&db, file)
-                .iter()
-                .map(|diagnostic| diagnostic.primary_message().to_string())
-                .collect::<Vec<_>>(),
-            vec!["Failed to read file: No such file or directory".to_string()]
+                .as_ref()
+                .unwrap_err()
+                .primary_message()
+                .to_string(),
+            "Failed to read file: No such file or directory".to_string()
         );
 
         let events = db.take_salsa_events();
@@ -778,6 +792,8 @@ mod tests {
         assert_eq!(source_text(&db, file).as_str(), "");
         assert_eq!(
             check_file_impl(&db, file)
+                .as_ref()
+                .unwrap()
                 .iter()
                 .map(|diagnostic| diagnostic.primary_message().to_string())
                 .collect::<Vec<_>>(),

crates/ty_python_semantic/resources/mdtest/attributes.md

@@ -2355,12 +2355,13 @@ import enum
 
 reveal_type(enum.Enum.__members__)  # revealed: MappingProxyType[str, Unknown]
 
-class Foo(enum.Enum):
-    BAR = 1
+class Answer(enum.Enum):
+    NO = 0
+    YES = 1
 
-reveal_type(Foo.BAR)  # revealed: Literal[Foo.BAR]
-reveal_type(Foo.BAR.value)  # revealed: Any
-reveal_type(Foo.__members__)  # revealed: MappingProxyType[str, Unknown]
+reveal_type(Answer.NO)  # revealed: Literal[Answer.NO]
+reveal_type(Answer.NO.value)  # revealed: Any
+reveal_type(Answer.__members__)  # revealed: MappingProxyType[str, Unknown]
 ```
 
 ## References

crates/ty_python_semantic/resources/mdtest/call/overloads.md

@@ -369,6 +369,8 @@ def _(x: type[A | B]):
 
 ### Expanding enums
 
+#### Basic
+
 `overloaded.pyi`:
 
 ```pyi
@@ -394,15 +396,106 @@ def f(x: Literal[SomeEnum.C]) -> C: ...
 ```
 
 ```py
+from typing import Literal
 from overloaded import SomeEnum, A, B, C, f
 
-def _(x: SomeEnum):
+def _(x: SomeEnum, y: Literal[SomeEnum.A, SomeEnum.C]):
     reveal_type(f(SomeEnum.A))  # revealed: A
     reveal_type(f(SomeEnum.B))  # revealed: B
     reveal_type(f(SomeEnum.C))  # revealed: C
-    # TODO: This should not be an error. The return type should be `A | B | C` once enums are expanded
-    # error: [no-matching-overload]
-    reveal_type(f(x))  # revealed: Unknown
+    reveal_type(f(x))  # revealed: A | B | C
+    reveal_type(f(y))  # revealed: A | C
+```
+
+#### Enum with single member
+
+This pattern appears in typeshed. Here, it is used to represent two optional, mutually exclusive
+keyword parameters:
+
+`overloaded.pyi`:
+
+```pyi
+from enum import Enum, auto
+from typing import overload, Literal
+
+class Missing(Enum):
+    Value = auto()
+
+class OnlyASpecified: ...
+class OnlyBSpecified: ...
+class BothMissing: ...
+
+@overload
+def f(*, a: int, b: Literal[Missing.Value] = ...) -> OnlyASpecified: ...
+@overload
+def f(*, a: Literal[Missing.Value] = ..., b: int) -> OnlyBSpecified: ...
+@overload
+def f(*, a: Literal[Missing.Value] = ..., b: Literal[Missing.Value] = ...) -> BothMissing: ...
+```
+
+```py
+from typing import Literal
+from overloaded import f, Missing
+
+reveal_type(f())  # revealed: BothMissing
+reveal_type(f(a=0))  # revealed: OnlyASpecified
+reveal_type(f(b=0))  # revealed: OnlyBSpecified
+
+f(a=0, b=0)  # error: [no-matching-overload]
+
+def _(missing: Literal[Missing.Value], missing_or_present: Literal[Missing.Value] | int):
+    reveal_type(f(a=missing, b=missing))  # revealed: BothMissing
+    reveal_type(f(a=missing))  # revealed: BothMissing
+    reveal_type(f(b=missing))  # revealed: BothMissing
+    reveal_type(f(a=0, b=missing))  # revealed: OnlyASpecified
+    reveal_type(f(a=missing, b=0))  # revealed: OnlyBSpecified
+
+    reveal_type(f(a=missing_or_present))  # revealed: BothMissing | OnlyASpecified
+    reveal_type(f(b=missing_or_present))  # revealed: BothMissing | OnlyBSpecified
+
+    # Here, both could be present, so this should be an error
+    f(a=missing_or_present, b=missing_or_present)  # error: [no-matching-overload]
+```
+
+#### Enum subclass without members
+
+An `Enum` subclass without members should *not* be expanded:
+
+`overloaded.pyi`:
+
+```pyi
+from enum import Enum
+from typing import overload, Literal
+
+class MyEnumSubclass(Enum):
+    pass
+
+class ActualEnum(MyEnumSubclass):
+    A = 1
+    B = 2
+
+class OnlyA: ...
+class OnlyB: ...
+class Both: ...
+
+@overload
+def f(x: Literal[ActualEnum.A]) -> OnlyA: ...
+@overload
+def f(x: Literal[ActualEnum.B]) -> OnlyB: ...
+@overload
+def f(x: ActualEnum) -> Both: ...
+@overload
+def f(x: MyEnumSubclass) -> MyEnumSubclass: ...
+```
+
+```py
+from overloaded import MyEnumSubclass, ActualEnum, f
+
+def _(actual_enum: ActualEnum, my_enum_instance: MyEnumSubclass):
+    reveal_type(f(actual_enum))  # revealed: Both
+    reveal_type(f(ActualEnum.A))  # revealed: OnlyA
+    reveal_type(f(ActualEnum.B))  # revealed: OnlyB
+    reveal_type(f(my_enum_instance))  # revealed: MyEnumSubclass
 ```
 
 ### No matching overloads

crates/ty_python_semantic/resources/mdtest/enums.md

@@ -570,7 +570,111 @@ To do: <https://typing.python.org/en/latest/spec/enums.html#enum-definition>
 
 ## Exhaustiveness checking
 
-To do
+## `if` statements
+
+```py
+from enum import Enum
+from typing_extensions import assert_never
+
+class Color(Enum):
+    RED = 1
+    GREEN = 2
+    BLUE = 3
+
+def color_name(color: Color) -> str:
+    if color is Color.RED:
+        return "Red"
+    elif color is Color.GREEN:
+        return "Green"
+    elif color is Color.BLUE:
+        return "Blue"
+    else:
+        assert_never(color)
+
+# No `invalid-return-type` error here because the implicit `else` branch is detected as unreachable:
+def color_name_without_assertion(color: Color) -> str:
+    if color is Color.RED:
+        return "Red"
+    elif color is Color.GREEN:
+        return "Green"
+    elif color is Color.BLUE:
+        return "Blue"
+
+def color_name_misses_one_variant(color: Color) -> str:
+    if color is Color.RED:
+        return "Red"
+    elif color is Color.GREEN:
+        return "Green"
+    else:
+        assert_never(color)  # error: [type-assertion-failure] "Argument does not have asserted type `Never`"
+
+class Singleton(Enum):
+    VALUE = 1
+
+def singleton_check(value: Singleton) -> str:
+    if value is Singleton.VALUE:
+        return "Singleton value"
+    else:
+        assert_never(value)
+```
+
+## `match` statements
+
+```toml
+[environment]
+python-version = "3.10"
+```
+
+```py
+from enum import Enum
+from typing_extensions import assert_never
+
+class Color(Enum):
+    RED = 1
+    GREEN = 2
+    BLUE = 3
+
+def color_name(color: Color) -> str:
+    match color:
+        case Color.RED:
+            return "Red"
+        case Color.GREEN:
+            return "Green"
+        case Color.BLUE:
+            return "Blue"
+        case _:
+            assert_never(color)
+
+# TODO: this should not be an error, see https://github.com/astral-sh/ty/issues/99#issuecomment-2983054488
+# error: [invalid-return-type] "Function can implicitly return `None`, which is not assignable to return type `str`"
+def color_name_without_assertion(color: Color) -> str:
+    match color:
+        case Color.RED:
+            return "Red"
+        case Color.GREEN:
+            return "Green"
+        case Color.BLUE:
+            return "Blue"
+
+def color_name_misses_one_variant(color: Color) -> str:
+    match color:
+        case Color.RED:
+            return "Red"
+        case Color.GREEN:
+            return "Green"
+        case _:
+            assert_never(color)  # error: [type-assertion-failure] "Argument does not have asserted type `Never`"
+
+class Singleton(Enum):
+    VALUE = 1
+
+def singleton_check(value: Singleton) -> str:
+    match value:
+        case Singleton.VALUE:
+            return "Singleton value"
+        case _:
+            assert_never(value)
+```
 
 ## References