Fix flaky diagnostic added by declaration emit for untyped module imports

tsc/internal/checker/checker.go

@@ -15379,7 +15379,10 @@ func (c *Checker) getExternalModuleFileFromDeclaration(declaration *ast.Node) *a
 	if ast.HasImportAttributes(declaration) {
 		importAttributesType = c.getTypeFromImportAttributes(ast.GetImportAttributes(declaration))
 	}
-	moduleSymbol := c.resolveExternalModuleNameWorker(specifier, specifier /*moduleNotFoundError*/, nil, false, false, importAttributesType) // TODO: GH#18217
+	// This is only used by emit and type printing, after checking has already reported any
+	// resolution errors for this specifier. Resolve with ignoreErrors so that these queries
+	// don't add new diagnostics (e.g. an implicit-any-module suggestion) as a side effect.
+	moduleSymbol := c.resolveExternalModuleNameWorker(specifier, specifier, nil /*moduleNotFoundError*/, true /*ignoreErrors*/, false /*isForAugmentation*/, importAttributesType)
 	if moduleSymbol == nil {
 		return nil
 	}

tsc/internal/fourslash/fourslash.go

@@ -166,6 +166,9 @@ type FourslashOptions struct {
 	Capabilities         *lsproto.ClientCapabilities
 	ContentMapperSpawner contentmapper.Spawner
 	RunExternalCode      bool
+	// Makes every textDocument/diagnostic request also emit the program and compare
+	// the diagnostics before and after emit, e.g. to catch ones added by the emit resolver.
+	TrackFlakyDiagnostics *lsproto.DiagnosticFlakeLogLevel
 }
 
 func NewFourslashWithOptions(t *testing.T, content string, options *FourslashOptions) (*FourslashTest, func()) {
@@ -260,7 +263,7 @@ func newFourslash(t *testing.T, content string, options *FourslashOptions, testP
 	// !!! temporary; remove when we have `handleDidChangeConfiguration`/implicit project config support
 	// !!! replace with a proper request *after initialize*
 	client.SetCompilerOptionsForInferredProjects(compilerOptions)
-	f.initialize(t, options.Capabilities, options.RunExternalCode)
+	f.initialize(t, options)
 
 	if testData.isStateBaseliningEnabled() {
 		// Single baseline, so initialize project state baseline too
@@ -365,11 +368,12 @@ func getBaseFileNameFromTest(t *testing.T) string {
 
 const showCodeLensLocationsCommandName = "typescript.showCodeLensLocations"
 
-func (f *FourslashTest) initialize(t *testing.T, capabilities *lsproto.ClientCapabilities, runExternalCode bool) {
+func (f *FourslashTest) initialize(t *testing.T, options *FourslashOptions) {
 	initializationOptions := &lsproto.InitializationOptions{
 		CodeLensShowLocationsCommandName: new(showCodeLensLocationsCommandName),
+		TrackFlakyDiagnostics:            options.TrackFlakyDiagnostics,
 	}
-	if runExternalCode {
+	if options.RunExternalCode {
 		initializationOptions.RunExternalCode = new(true)
 	}
 	params := &lsproto.InitializeParams{
@@ -378,7 +382,7 @@ func (f *FourslashTest) initialize(t *testing.T, capabilities *lsproto.ClientCap
 			InitializationOptions: initializationOptions,
 		},
 	}
-	params.Capabilities = getCapabilitiesWithDefaults(capabilities)
+	params.Capabilities = getCapabilitiesWithDefaults(options.Capabilities)
 	f.capabilities = params.Capabilities
 	resp, _, ok := f.client.SendRequest(t, lsproto.InitializeInfo, params)
 	if !ok {

tsc/internal/testutil/harnessutil/harnessutil.go

@@ -663,12 +663,12 @@ func compileFilesWithHost(
 	preErrors = append(preErrors, preProgram.GetSyntacticDiagnostics(ctx, nil)...)
 	preErrors = append(preErrors, preProgram.GetSemanticDiagnostics(ctx, nil)...)
 	preErrors = append(preErrors, preProgram.GetGlobalDiagnostics(ctx)...)
-	if preProgram.Options().GetEmitDeclarations() {
-		preErrors = append(preErrors, preProgram.GetDeclarationDiagnostics(ctx, nil)...)
-	}
 	if harnessOptions.CaptureSuggestions {
 		preErrors = append(preErrors, preProgram.GetSuggestionDiagnostics(ctx, nil)...)
 	}
+	if preProgram.Options().GetEmitDeclarations() {
+		preErrors = append(preErrors, preProgram.GetDeclarationDiagnostics(ctx, nil)...)
+	}
 	preErrors = compiler.SortAndDeduplicateDiagnostics(preErrors)
 
 	postProgram := createProgram(host, config)

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule1.js

@@ -0,0 +1,16 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule1.ts] ////
+
+//// [index.js]
+exports.x = 1;
+//// [index.js]
+import { x } from "untyped";
+x;
+
+
+//// [index.js]
+import { x } from "untyped";
+x;
+
+
+//// [index.d.ts]
+export {};

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule1.symbols

@@ -0,0 +1,9 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule1.ts] ////
+
+=== /index.js ===
+import { x } from "untyped";
+>x : Symbol(x, Decl(index.js, 0, 8))
+
+x;
+>x : Symbol(x, Decl(index.js, 0, 8))
+

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule1.types

@@ -0,0 +1,9 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule1.ts] ////
+
+=== /index.js ===
+import { x } from "untyped";
+>x : any
+
+x;
+>x : error
+

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule2.js

@@ -0,0 +1,18 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule2.ts] ////
+
+//// [untyped.js]
+exports.x = 1;
+//// [index.ts]
+// @ts-expect-error
+import { x } from "./untyped";
+x;
+
+
+//// [index.js]
+// @ts-expect-error
+import { x } from "./untyped";
+x;
+
+
+//// [index.d.ts]
+export {};

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule2.symbols

@@ -0,0 +1,10 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule2.ts] ////
+
+=== /index.ts ===
+// @ts-expect-error
+import { x } from "./untyped";
+>x : Symbol(x, Decl(index.ts, 1, 8))
+
+x;
+>x : Symbol(x, Decl(index.ts, 1, 8))
+

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule2.types

@@ -0,0 +1,10 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule2.ts] ////
+
+=== /index.ts ===
+// @ts-expect-error
+import { x } from "./untyped";
+>x : any
+
+x;
+>x : error
+

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule3.js

@@ -0,0 +1,18 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule3.ts] ////
+
+//// [untyped.mjs]
+export const x = 1;
+//// [index.mts]
+// @ts-expect-error
+import { x } from "./untyped.mjs";
+x;
+
+
+//// [index.mjs]
+// @ts-expect-error
+import { x } from "./untyped.mjs";
+x;
+
+
+//// [index.d.mts]
+export {};

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule3.symbols

@@ -0,0 +1,10 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule3.ts] ////
+
+=== /index.mts ===
+// @ts-expect-error
+import { x } from "./untyped.mjs";
+>x : Symbol(x, Decl(index.mts, 1, 8))
+
+x;
+>x : Symbol(x, Decl(index.mts, 1, 8))
+

tsc/testdata/baselines/reference/compiler/noFlakyDiagnosticsUntypedModule3.types

@@ -0,0 +1,10 @@
+//// [tests/cases/compiler/noFlakyDiagnosticsUntypedModule3.ts] ////
+
+=== /index.mts ===
+// @ts-expect-error
+import { x } from "./untyped.mjs";
+>x : any
+
+x;
+>x : error
+

tsc/testdata/tests/cases/compiler/noFlakyDiagnosticsUntypedModule1.ts

@@ -0,0 +1,11 @@
+// @allowJs: true
+// @noImplicitAny: true
+// @declaration: true
+// @outDir: /out
+// @noImplicitReferences: true
+// @captureSuggestions: true
+// @Filename: /node_modules/untyped/index.js
+exports.x = 1;
+// @Filename: /index.js
+import { x } from "untyped";
+x;

tsc/testdata/tests/cases/compiler/noFlakyDiagnosticsUntypedModule2.ts

@@ -0,0 +1,10 @@
+// @noImplicitAny: true
+// @declaration: true
+// @noImplicitReferences: true
+// @captureSuggestions: true
+// @Filename: /untyped.js
+exports.x = 1;
+// @Filename: /index.ts
+// @ts-expect-error
+import { x } from "./untyped";
+x;

tsc/testdata/tests/cases/compiler/noFlakyDiagnosticsUntypedModule3.ts

@@ -0,0 +1,11 @@
+// @module: nodenext
+// @noImplicitAny: true
+// @declaration: true
+// @noImplicitReferences: true
+// @captureSuggestions: true
+// @Filename: /untyped.mjs
+export const x = 1;
+// @Filename: /index.mts
+// @ts-expect-error
+import { x } from "./untyped.mjs";
+x;