[ty] Fix duplicate diagnostics for unresolved module when an import from statement imports multiple members (#17886)

crates/ty/tests/cli.rs

@@ -276,7 +276,7 @@ fn cli_arguments_are_relative_to_the_current_directory() -> anyhow::Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    error: lint:unresolved-import: Cannot resolve import `utils`
+    error: lint:unresolved-import: Cannot resolve imported module `utils`
      --> test.py:2:6
       |
     2 | from utils import add
@@ -452,7 +452,7 @@ fn cli_rule_severity() -> anyhow::Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    error: lint:unresolved-import: Cannot resolve import `does_not_exit`
+    error: lint:unresolved-import: Cannot resolve imported module `does_not_exit`
      --> test.py:2:8
       |
     2 | import does_not_exit
@@ -499,7 +499,7 @@ fn cli_rule_severity() -> anyhow::Result<()> {
     success: true
     exit_code: 0
     ----- stdout -----
-    warning: lint:unresolved-import: Cannot resolve import `does_not_exit`
+    warning: lint:unresolved-import: Cannot resolve imported module `does_not_exit`
      --> test.py:2:8
       |
     2 | import does_not_exit
@@ -1053,7 +1053,7 @@ fn check_specific_paths() -> anyhow::Result<()> {
       |     ^^^^^
       |
 
-    error: lint:unresolved-import: Cannot resolve import `main2`
+    error: lint:unresolved-import: Cannot resolve imported module `main2`
      --> project/other.py:2:6
       |
     2 | from main2 import z  # error: unresolved-import
@@ -1062,7 +1062,7 @@ fn check_specific_paths() -> anyhow::Result<()> {
     4 | print(z)
       |
 
-    error: lint:unresolved-import: Cannot resolve import `does_not_exist`
+    error: lint:unresolved-import: Cannot resolve imported module `does_not_exist`
      --> project/tests/test_main.py:2:8
       |
     2 | import does_not_exist  # error: unresolved-import
@@ -1083,7 +1083,7 @@ fn check_specific_paths() -> anyhow::Result<()> {
     success: false
     exit_code: 1
     ----- stdout -----
-    error: lint:unresolved-import: Cannot resolve import `main2`
+    error: lint:unresolved-import: Cannot resolve imported module `main2`
      --> project/other.py:2:6
       |
     2 | from main2 import z  # error: unresolved-import
@@ -1092,7 +1092,7 @@ fn check_specific_paths() -> anyhow::Result<()> {
     4 | print(z)
       |
 
-    error: lint:unresolved-import: Cannot resolve import `does_not_exist`
+    error: lint:unresolved-import: Cannot resolve imported module `does_not_exist`
      --> project/tests/test_main.py:2:8
       |
     2 | import does_not_exist  # error: unresolved-import

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

@@ -16,7 +16,7 @@ def _(flag: bool):
 ## Calling with an unknown union
 
 ```py
-from nonexistent import f  # error: [unresolved-import] "Cannot resolve import `nonexistent`"
+from nonexistent import f  # error: [unresolved-import] "Cannot resolve imported module `nonexistent`"
 
 def coinflip() -> bool:
     return True

crates/ty_python_semantic/resources/mdtest/import/basic.md

@@ -121,7 +121,7 @@ class C: ...
 <!-- snapshot-diagnostics -->
 
 ```py
-import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzqzqzqzqzqzq`"
+import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve imported module `zqzqzqzqzqzqzq`"
 ```
 
 ## Unresolvable submodule imports
@@ -130,10 +130,10 @@ import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzq
 
 ```py
 # Topmost component resolvable, submodule not resolvable:
-import a.foo  # error: [unresolved-import] "Cannot resolve import `a.foo`"
+import a.foo  # error: [unresolved-import] "Cannot resolve imported module `a.foo`"
 
 # Topmost component unresolvable:
-import b.foo  # error: [unresolved-import] "Cannot resolve import `b.foo`"
+import b.foo  # error: [unresolved-import] "Cannot resolve imported module `b.foo`"
 ```
 
 `a/__init__.py`:
@@ -164,3 +164,15 @@ from AveryLongPathAveryLongPathAveryLongPathAveryLongPathAveryLongPathAveryLongP
 
 reveal_type(Foo())  # revealed: Foo
 ```
+
+## Multiple objects imported from an unresolved module
+
+<!-- snapshot-diagnostics -->
+
+If multiple members are imported from a module that cannot be resolved, only a single diagnostic is
+emitted for the `import from` statement:
+
+```py
+# error: [unresolved-import]
+from does_not_exist import foo, bar, baz
+```

crates/ty_python_semantic/resources/mdtest/import/errors.md

@@ -3,7 +3,7 @@
 ## Unresolved import statement
 
 ```py
-import bar  # error: "Cannot resolve import `bar`"
+import bar  # error: "Cannot resolve imported module `bar`"
 
 reveal_type(bar)  # revealed: Unknown
 ```
@@ -11,7 +11,7 @@ reveal_type(bar)  # revealed: Unknown
 ## Unresolved import from statement
 
 ```py
-from bar import baz  # error: "Cannot resolve import `bar`"
+from bar import baz  # error: "Cannot resolve imported module `bar`"
 
 reveal_type(baz)  # revealed: Unknown
 ```
@@ -34,7 +34,7 @@ reveal_type(thing)  # revealed: Unknown
 `a.py`:
 
 ```py
-import foo as foo  # error: "Cannot resolve import `foo`"
+import foo as foo  # error: "Cannot resolve imported module `foo`"
 
 reveal_type(foo)  # revealed: Unknown
 ```

crates/ty_python_semantic/resources/mdtest/import/star.md

@@ -1369,7 +1369,7 @@ If the module is unresolved, we emit a diagnostic just like for any other unreso
 
 ```py
 # TODO: not a great error message
-from foo import *  # error: [unresolved-import] "Cannot resolve import `foo`"
+from foo import *  # error: [unresolved-import] "Cannot resolve imported module `foo`"
 ```
 
 ### Nested scope

crates/ty_python_semantic/resources/mdtest/mdtest_custom_typeshed.md

@@ -81,7 +81,7 @@ new_module: 3.11-
 ```py
 from old_module import OldClass
 
-# error: [unresolved-import] "Cannot resolve import `new_module`"
+# error: [unresolved-import] "Cannot resolve imported module `new_module`"
 from new_module import NewClass
 ```
 

crates/ty_python_semantic/resources/mdtest/mro.md

@@ -313,7 +313,6 @@ reveal_type(Omelette.__mro__)  # revealed: tuple[Literal[Omelette], Unknown, Lit
 
 ```py
 # error: [unresolved-import]
-# error: [unresolved-import]
 from does_not_exist import unknown_object_1, unknown_object_2
 
 reveal_type(unknown_object_1)  # revealed: Unknown

crates/ty_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Multiple_objects_imported_from_an_unresolved_module.snap

@@ -0,0 +1,30 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: basic.md - Structures - Multiple objects imported from an unresolved module
+mdtest path: crates/ty_python_semantic/resources/mdtest/import/basic.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+1 | # error: [unresolved-import]
+2 | from does_not_exist import foo, bar, baz
+```
+
+# Diagnostics
+
+```
+error: lint:unresolved-import: Cannot resolve imported module `does_not_exist`
+ --> src/mdtest_snippet.py:2:6
+  |
+1 | # error: [unresolved-import]
+2 | from does_not_exist import foo, bar, baz
+  |      ^^^^^^^^^^^^^^
+  |
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_module_import.snap

@@ -12,16 +12,16 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/import/basic.md
 ## mdtest_snippet.py
 
 ```
-1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzqzqzqzqzqzq`"
+1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve imported module `zqzqzqzqzqzqzq`"
 ```
 
 # Diagnostics
 
 ```
-error: lint:unresolved-import: Cannot resolve import `zqzqzqzqzqzqzq`
+error: lint:unresolved-import: Cannot resolve imported module `zqzqzqzqzqzqzq`
  --> src/mdtest_snippet.py:1:8
   |
-1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzqzqzqzqzqzq`"
+1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve imported module `zqzqzqzqzqzqzq`"
   |        ^^^^^^^^^^^^^^
   |
 

crates/ty_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_submodule_imports.snap

@@ -13,10 +13,10 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/import/basic.md
 
 ```
 1 | # Topmost component resolvable, submodule not resolvable:
-2 | import a.foo  # error: [unresolved-import] "Cannot resolve import `a.foo`"
+2 | import a.foo  # error: [unresolved-import] "Cannot resolve imported module `a.foo`"
 3 | 
 4 | # Topmost component unresolvable:
-5 | import b.foo  # error: [unresolved-import] "Cannot resolve import `b.foo`"
+5 | import b.foo  # error: [unresolved-import] "Cannot resolve imported module `b.foo`"
 ```
 
 ## a/__init__.py
@@ -27,11 +27,11 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/import/basic.md
 # Diagnostics
 
 ```
-error: lint:unresolved-import: Cannot resolve import `a.foo`
+error: lint:unresolved-import: Cannot resolve imported module `a.foo`
  --> src/mdtest_snippet.py:2:8
   |
 1 | # Topmost component resolvable, submodule not resolvable:
-2 | import a.foo  # error: [unresolved-import] "Cannot resolve import `a.foo`"
+2 | import a.foo  # error: [unresolved-import] "Cannot resolve imported module `a.foo`"
   |        ^^^^^
 3 |
 4 | # Topmost component unresolvable:
@@ -40,11 +40,11 @@ error: lint:unresolved-import: Cannot resolve import `a.foo`
 ```
 
 ```
-error: lint:unresolved-import: Cannot resolve import `b.foo`
+error: lint:unresolved-import: Cannot resolve imported module `b.foo`
  --> src/mdtest_snippet.py:5:8
   |
 4 | # Topmost component unresolvable:
-5 | import b.foo  # error: [unresolved-import] "Cannot resolve import `b.foo`"
+5 | import b.foo  # error: [unresolved-import] "Cannot resolve imported module `b.foo`"
   |        ^^^^^
   |
 

crates/ty_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_An_unresolvable_import_that_does_not_use_`from`.snap

@@ -20,7 +20,7 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/unresolved_i
 # Diagnostics
 
 ```
-error: lint:unresolved-import: Cannot resolve import `does_not_exist`
+error: lint:unresolved-import: Cannot resolve imported module `does_not_exist`
  --> src/mdtest_snippet.py:1:8
   |
 1 | import does_not_exist  # error: [unresolved-import]

crates/ty_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_an_unknown_current_module.snap

@@ -20,7 +20,7 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/unresolved_i
 # Diagnostics
 
 ```
-error: lint:unresolved-import: Cannot resolve import `.does_not_exist`
+error: lint:unresolved-import: Cannot resolve imported module `.does_not_exist`
  --> src/mdtest_snippet.py:1:7
   |
 1 | from .does_not_exist import add  # error: [unresolved-import]

crates/ty_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_an_unknown_nested_module.snap

@@ -20,7 +20,7 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/unresolved_i
 # Diagnostics
 
 ```
-error: lint:unresolved-import: Cannot resolve import `.does_not_exist.foo.bar`
+error: lint:unresolved-import: Cannot resolve imported module `.does_not_exist.foo.bar`
  --> src/mdtest_snippet.py:1:7
   |
 1 | from .does_not_exist.foo.bar import add  # error: [unresolved-import]

crates/ty_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_an_unresolvable_module.snap

@@ -20,7 +20,7 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/unresolved_i
 # Diagnostics
 
 ```
-error: lint:unresolved-import: Cannot resolve import `does_not_exist`
+error: lint:unresolved-import: Cannot resolve imported module `does_not_exist`
  --> src/mdtest_snippet.py:1:6
   |
 1 | from does_not_exist import add  # error: [unresolved-import]

crates/ty_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_too_many_leading_dots.snap

@@ -32,7 +32,7 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/unresolved_i
 # Diagnostics
 
 ```
-error: lint:unresolved-import: Cannot resolve import `....foo`
+error: lint:unresolved-import: Cannot resolve imported module `....foo`
  --> src/package/subpackage/subsubpackage/__init__.py:1:10
   |
 1 | from ....foo import add  # error: [unresolved-import]

crates/ty_python_semantic/src/types/infer.rs

@@ -3612,7 +3612,7 @@ impl<'db> TypeInferenceBuilder<'db> {
             return;
         };
         builder.into_diagnostic(format_args!(
-            "Cannot resolve import `{}{}`",
+            "Cannot resolve imported module `{}{}`",
             ".".repeat(level as usize),
             module.unwrap_or_default()
         ));
@@ -3680,21 +3680,14 @@ impl<'db> TypeInferenceBuilder<'db> {
             level: _,
         } = import;
 
+        self.check_import_from_module_is_resolvable(import);
+
         for alias in names {
-            let definitions = self.index.definitions(alias);
+            for definition in self.index.definitions(alias) {
-            if definitions.is_empty() {
-                // If the module couldn't be resolved while constructing the semantic index,
-                // this node won't have any definitions associated with it -- but we need to
-                // make sure that we still emit the diagnostic for the unresolvable module,
-                // since this will cause the import to fail at runtime.
-                self.resolve_import_from_module(import, alias);
-            } else {
-                for definition in definitions {
                 self.extend(infer_definition_types(self.db(), *definition));
             }
         }
     }
-    }
 
     fn infer_assert_statement(&mut self, assert: &ast::StmtAssert) {
         let ast::StmtAssert {
@@ -3746,11 +3739,7 @@ impl<'db> TypeInferenceBuilder<'db> {
 
     /// Resolve the [`ModuleName`], and the type of the module, being referred to by an
     /// [`ast::StmtImportFrom`] node. Emit a diagnostic if the module cannot be resolved.
-    fn resolve_import_from_module(
+    fn check_import_from_module_is_resolvable(&mut self, import_from: &ast::StmtImportFrom) {
-        &mut self,
-        import_from: &ast::StmtImportFrom,
-        alias: &ast::Alias,
-    ) -> Option<(ModuleName, Type<'db>)> {
         let ast::StmtImportFrom { module, level, .. } = import_from;
 
         // For diagnostics, we want to highlight the unresolvable
@@ -3762,8 +3751,7 @@ impl<'db> TypeInferenceBuilder<'db> {
         let module = module.as_deref();
 
         tracing::trace!(
-            "Resolving imported object `{}` from module `{}` into file `{}`",
+            "Resolving import statement from module `{}` into file `{}`",
-            alias.name,
             format_import_from_module(*level, module),
             self.file().path(self.db()),
         );
@@ -3774,7 +3762,7 @@ impl<'db> TypeInferenceBuilder<'db> {
             Err(ModuleNameResolutionError::InvalidSyntax) => {
                 tracing::debug!("Failed to resolve import due to invalid syntax");
                 // Invalid syntax diagnostics are emitted elsewhere.
-                return None;
+                return;
             }
             Err(ModuleNameResolutionError::TooManyDots) => {
                 tracing::debug!(
@@ -3787,7 +3775,7 @@ impl<'db> TypeInferenceBuilder<'db> {
                     *level,
                     module,
                 );
-                return None;
+                return;
             }
             Err(ModuleNameResolutionError::UnknownCurrentModule) => {
                 tracing::debug!(
@@ -3801,16 +3789,13 @@ impl<'db> TypeInferenceBuilder<'db> {
                     *level,
                     module,
                 );
-                return None;
+                return;
             }
         };
 
-        let Some(module_ty) = self.module_type_from_name(&module_name) else {
+        if resolve_module(self.db(), &module_name).is_none() {
             self.report_unresolved_import(import_from.into(), module_ref.range(), *level, module);
-            return None;
+        }
-        };
-
-        Some((module_name, module_ty))
     }
 
     fn infer_import_from_definition(
@@ -3819,12 +3804,18 @@ impl<'db> TypeInferenceBuilder<'db> {
         alias: &ast::Alias,
         definition: Definition<'db>,
     ) {
-        let Some((module_name, module_ty)) = self.resolve_import_from_module(import_from, alias)
+        let Ok(module_name) =
+            ModuleName::from_import_statement(self.db(), self.file(), import_from)
         else {
             self.add_unknown_declaration_with_binding(alias.into(), definition);
             return;
         };
 
+        let Some(module_ty) = self.module_type_from_name(&module_name) else {
+            self.add_unknown_declaration_with_binding(alias.into(), definition);
+            return;
+        };
+
         // The indirection of having `star_import_info` as a separate variable
         // is required in order to make the borrow checker happy.
         let star_import_info = definition

crates/ty_wasm/tests/api.rs

@@ -27,5 +27,8 @@ fn check() {
         diagnostic.to_range(&workspace).unwrap().start,
         Position { line: 1, column: 8 }
     );
-    assert_eq!(diagnostic.message(), "Cannot resolve import `random22`");
+    assert_eq!(
+        diagnostic.message(),
+        "Cannot resolve imported module `random22`"
+    );
 }