Fix completions for unpacking TypeDicts with missing fields

packages/pyright-internal/src/analyzer/typeEvaluator.ts

@@ -12503,13 +12503,28 @@ export function createTypeEvaluator(
 
         if (matchResults.argumentErrors) {
             // Evaluate types of all args. This will ensure that referenced symbols are
-            // not reported as unaccessed.
+            // not reported as unaccessed. Also pass the expected parameter type as
+            // inference context to enable proper completions even when there are errors.
+            matchResults.argParams.forEach((argParam) => {
+                if (argParam.argument.valueExpression && !isSpeculativeModeInUse(argParam.argument.valueExpression)) {
+                    getTypeOfExpression(
+                        argParam.argument.valueExpression,
+                        /* flags */ undefined,
+                        makeInferenceContext(argParam.paramType)
+                    );
+                }
+            });
+
+            // Also evaluate any arguments that weren't matched to parameters
             argList.forEach((arg) => {
                 if (arg.valueExpression && !isSpeculativeModeInUse(arg.valueExpression)) {
-                    getTypeOfExpression(arg.valueExpression);
+                    // Check if this argument was already evaluated above
+                    const wasEvaluated = matchResults.argParams.some((argParam) => argParam.argument === arg);
+                    if (!wasEvaluated) {
+                        getTypeOfExpression(arg.valueExpression);
+                    }
                 }
             });
-
             // Use a return type of Unknown but attach a "possible type" to it
             // so the completion provider can suggest better completions.
             const possibleType = FunctionType.getEffectiveReturnType(typeResult.type);
@@ -12786,7 +12801,10 @@ export function createTypeEvaluator(
             if (argParam.argType) {
                 argType = argParam.argType;
             } else {
-                const argTypeResult = getTypeOfArg(argParam.argument, /* inferenceContext */ undefined);
+                const argTypeResult = getTypeOfArg(
+                    argParam.argument,
+                    makeInferenceContext(argParam.paramType, isTypeIncomplete)
+                );
                 argType = argTypeResult.type;
                 if (argTypeResult.isIncomplete) {
                     isTypeIncomplete = true;

packages/pyright-internal/src/tests/completions.test.ts

@@ -1480,3 +1480,116 @@ test('overloaded Literal[...] suggestions in call arguments', async () => {
         },
     });
 });
+
+test('nested TypedDict completion with Unpack - without other fields', async () => {
+    const code = `
+// @filename: test.py
+//// from typing import Unpack, TypedDict
+//// 
+//// class InnerDict(TypedDict):
+////     a: int
+////     b: str
+//// 
+//// class OuterDict(TypedDict):
+////     inner: InnerDict
+////     field_1: str
+//// 
+//// def test_inner_dict(**kwargs: Unpack[OuterDict]):
+////     pass
+//// 
+//// test_inner_dict(inner={[|/*marker*/|]})
+    `;
+
+    const state = parseAndGetTestState(code).state;
+
+    await state.verifyCompletion('included', 'markdown', {
+        marker: {
+            completions: [
+                {
+                    kind: CompletionItemKind.Constant,
+                    label: "'a'",
+                    textEdit: { range: state.getPositionRange('marker'), newText: "'a'" },
+                },
+                {
+                    kind: CompletionItemKind.Constant,
+                    label: "'b'",
+                    textEdit: { range: state.getPositionRange('marker'), newText: "'b'" },
+                },
+            ],
+        },
+    });
+});
+
+test('nested TypedDict completion with Unpack - with other fields', async () => {
+    const code = `
+// @filename: test.py
+//// from typing import Unpack, TypedDict
+//// 
+//// class InnerDict(TypedDict):
+////     a: int
+////     b: str
+//// 
+//// class OuterDict(TypedDict):
+////     inner: InnerDict
+////     field_1: str
+//// 
+//// def test_inner_dict(**kwargs: Unpack[OuterDict]):
+////     pass
+//// 
+//// test_inner_dict(field_1="test", inner={[|/*marker*/|]})
+    `;
+
+    const state = parseAndGetTestState(code).state;
+
+    await state.verifyCompletion('included', 'markdown', {
+        marker: {
+            completions: [
+                {
+                    kind: CompletionItemKind.Constant,
+                    label: '"a"',
+                    textEdit: { range: state.getPositionRange('marker'), newText: '"a"' },
+                },
+                {
+                    kind: CompletionItemKind.Constant,
+                    label: '"b"',
+                    textEdit: { range: state.getPositionRange('marker'), newText: '"b"' },
+                },
+            ],
+        },
+    });
+});
+
+test('simple nested TypedDict completion - no Unpack', async () => {
+    const code = `
+// @filename: test.py
+//// from typing import TypedDict
+//// 
+//// class InnerDict(TypedDict):
+////     a: int
+////     b: str
+//// 
+//// def test_func(inner: InnerDict):
+////     pass
+//// 
+//// test_func(inner={[|/*marker*/|]})
+    `;
+
+    const state = parseAndGetTestState(code).state;
+
+    await state.verifyCompletion('included', 'markdown', {
+        marker: {
+            completions: [
+                {
+                    kind: CompletionItemKind.Constant,
+                    label: "'a'",
+                    textEdit: { range: state.getPositionRange('marker'), newText: "'a'" },
+                },
+                {
+                    kind: CompletionItemKind.Constant,
+                    label: "'b'",
+                    textEdit: { range: state.getPositionRange('marker'), newText: "'b'" },
+                },
+            ],
+        },
+    });
+});