feat: Add "Fix all: X" code action for codefixes appearing multiple times in a file

.chronus/changes/codefix-fix-all-2026-7-30.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@typespec/compiler"
+---
+
+Add `Fix all: X` code action for codefixes that can be applied to multiple instances in a file at once. When a codefix applies to more than one diagnostic of the same kind in a file, a `Fix all: <fix label>` quick fix action is now suggested alongside the individual fix.

.chronus/changes/codefix-fix-all-playground-2026-7-30.md

@@ -0,0 +1,7 @@
+---
+changeKind: feature
+packages:
+  - "@typespec/playground"
+---
+
+Add support for the `Fix all: X` code action in the playground, allowing a codefix that appears multiple times in a file to be applied to all instances at once.

packages/compiler/src/server/serverlib.ts

@@ -177,7 +177,11 @@ export function createServer(
     log,
     clientConfigsProvider,
   });
-  let currentDiagnosticIndex = new Map<number, Diagnostic>();
+  interface DiagnosticIndexEntry {
+    readonly diagnostic: Diagnostic;
+    readonly fileUri: string;
+  }
+  let currentDiagnosticIndex = new Map<number, DiagnosticIndexEntry>();
   let diagnosticIdCounter = 0;
 
   let workspaceFolders: ServerWorkspaceFolder[] = [];
@@ -789,7 +793,7 @@ export function createServer(
     if (!document) return undefined;
     if (isTspConfigFile(document)) return undefined;
 
-    const newDiagnosticIndex = new Map<number, Diagnostic>();
+    const newDiagnosticIndex = new Map<number, DiagnosticIndexEntry>();
     // Group diagnostics by file.
     //
     // Initialize diagnostics for all source files in program to empty array
@@ -862,7 +866,7 @@ export function createServer(
           "Diagnostic reported against a source file that was not added to the program.",
         );
         diagnostics.push(diagnostic);
-        newDiagnosticIndex.set(diagnostic.data.id, each);
+        newDiagnosticIndex.set(diagnostic.data.id, { diagnostic: each, fileUri: diagDocument.uri });
       }
     }
 
@@ -894,7 +898,10 @@ export function createServer(
           "Diagnostic reported against a source file that was not added to the program.",
         );
         diagnostics.push(diagnostic);
-        newDiagnosticIndex.set(diagnostic.data.id, unusedSuppressionDiagnostic);
+        newDiagnosticIndex.set(diagnostic.data.id, {
+          diagnostic: unusedSuppressionDiagnostic,
+          fileUri: diagDocument.uri,
+        });
       }
     }
 
@@ -1411,33 +1418,84 @@ export function createServer(
   async function getCodeActions(params: CodeActionParams): Promise<CodeAction[]> {
     if (isTspConfigFile(params.textDocument)) return [];
 
-    const actions = [];
+    const fileUri = params.textDocument.uri;
+    const actions: CodeAction[] = [];
+
+    // Track fix IDs seen in the current selection to generate "Fix all" actions
+    const fixIdsInSelection = new Set<string>();
+
     for (const vsDiag of params.context.diagnostics) {
-      const tspDiag = currentDiagnosticIndex.get(vsDiag.data?.id);
-      if (tspDiag === undefined || tspDiag.codefixes === undefined) continue;
+      const entry = currentDiagnosticIndex.get(vsDiag.data?.id);
+      if (entry === undefined || entry.diagnostic.codefixes === undefined) continue;
 
-      for (const fix of tspDiag.codefixes ?? []) {
+      for (const fix of entry.diagnostic.codefixes) {
         const codeAction: CodeAction = {
           title: fix.label,
           kind: CodeActionKind.QuickFix,
           diagnostics: [vsDiag],
           data: { diagId: vsDiag.data?.id, fixId: fix.id },
         };
         actions.push(codeAction);
+        fixIdsInSelection.add(fix.id);
+      }
+    }
+
+    // Build a map of fixId -> { count, label } for all diagnostics in the current file
+    const fixIdInfoInFile = new Map<string, { count: number; label: string }>();
+    for (const entry of currentDiagnosticIndex.values()) {
+      if (entry.fileUri !== fileUri) continue;
+      for (const fix of entry.diagnostic.codefixes ?? []) {
+        const existing = fixIdInfoInFile.get(fix.id);
+        if (existing) {
+          existing.count++;
+        } else {
+          fixIdInfoInFile.set(fix.id, { count: 1, label: fix.label });
+        }
+      }
+    }
+
+    // Add "Fix all: X" actions for codefixes that appear multiple times in the file
+    const addedFixAllIds = new Set<string>();
+    for (const fixId of fixIdsInSelection) {
+      const info = fixIdInfoInFile.get(fixId);
+      if (info && info.count > 1 && !addedFixAllIds.has(fixId)) {
+        addedFixAllIds.add(fixId);
+        actions.push({
+          title: `Fix all: ${info.label}`,
+          kind: CodeActionKind.QuickFix,
+          data: { fixAllInFile: { fixId, fileUri } },
+        });
       }
     }
 
     return actions;
   }
 
   async function resolveCodeAction(codeAction: CodeAction): Promise<CodeAction> {
-    const { diagId, fixId } = codeAction.data ?? {};
-    if (diagId !== undefined && fixId) {
-      const diag = currentDiagnosticIndex.get(diagId);
-      const codeFix = diag?.codefixes?.find((x) => x.id === fixId);
-      if (codeFix) {
-        const edits = await resolveCodeFix(codeFix);
-        codeAction.edit = { documentChanges: convertCodeFixEdits(edits) };
+    const data = codeAction.data ?? {};
+    if (data.fixAllInFile !== undefined) {
+      const { fixId, fileUri } = data.fixAllInFile;
+      const allEdits: CodeFixEdit[] = [];
+      for (const entry of currentDiagnosticIndex.values()) {
+        if (entry.fileUri !== fileUri) continue;
+        const codeFix = entry.diagnostic.codefixes?.find((x) => x.id === fixId);
+        if (codeFix) {
+          const edits = await resolveCodeFix(codeFix);
+          allEdits.push(...edits);
+        }
+      }
+      if (allEdits.length > 0) {
+        codeAction.edit = { documentChanges: convertCodeFixEdits(allEdits) };
+      }
+    } else {
+      const { diagId, fixId } = data;
+      if (diagId !== undefined && fixId) {
+        const entry = currentDiagnosticIndex.get(diagId);
+        const codeFix = entry?.diagnostic.codefixes?.find((x) => x.id === fixId);
+        if (codeFix) {
+          const edits = await resolveCodeFix(codeFix);
+          codeAction.edit = { documentChanges: convertCodeFixEdits(edits) };
+        }
       }
     }
     return codeAction;

packages/compiler/test/server/code-actions.test.ts

@@ -0,0 +1,101 @@
+import { beforeEach, describe, expect, it } from "vitest";
+import { CodeAction, CodeActionKind, Diagnostic, Range } from "vscode-languageserver";
+import { createTestServerHost, TestServerHost } from "../../src/testing/test-server-host.js";
+
+let host: TestServerHost;
+
+beforeEach(async () => {
+  host = await createTestServerHost();
+});
+
+/** Add the given files, compile `main.tsp` and return its diagnostics. */
+async function compileAndGetDiagnostics(
+  files: Record<string, string>,
+): Promise<readonly Diagnostic[]> {
+  let mainFile;
+  for (const [path, content] of Object.entries(files)) {
+    const doc = host.addOrUpdateDocument(path, content);
+    if (path.endsWith("main.tsp")) {
+      mainFile = doc;
+    }
+  }
+
+  await host.server.compile(mainFile!, undefined, { mode: "full" });
+  return host.getDiagnostics("main.tsp");
+}
+
+function getCodeActions(diagnostics: Diagnostic[]): Promise<CodeAction[]> {
+  return host.server.getCodeActions({
+    textDocument: { uri: host.getURL("main.tsp") },
+    range: Range.create(0, 0, 0, 0),
+    context: { diagnostics },
+  });
+}
+
+describe("Fix all: X actions", () => {
+  it("shows 'Fix all: X' action when same codefix appears multiple times in the file", async () => {
+    const diags = await compileAndGetDiagnostics({
+      "./sub.tsp": "namespace Foo; model FooModel {};",
+      "./sub2.tsp": "namespace Bar; model BarModel {};",
+      "./main.tsp": 'import "./sub.tsp";\nimport "./sub2.tsp";\nusing Foo;\nusing Bar;',
+    });
+
+    // Both "using Foo" and "using Bar" are unused → 2 diagnostics with same codefix id
+    expect(diags.length).toBeGreaterThanOrEqual(2);
+
+    const actions = await getCodeActions([diags[0]]);
+
+    // Should include an individual fix
+    expect(actions.some((a) => a.kind === CodeActionKind.QuickFix && !a.data?.fixAllInFile)).toBe(
+      true,
+    );
+
+    // Should include a "Fix all: Remove unused code" action
+    const fixAllAction = actions.find(
+      (a) => a.kind === CodeActionKind.QuickFix && a.data?.fixAllInFile !== undefined,
+    );
+    expect(fixAllAction).toBeDefined();
+    expect(fixAllAction?.title).toBe("Fix all: Remove unused code");
+  });
+
+  it("does NOT show 'Fix all: X' action when codefix only appears once in the file", async () => {
+    const diags = await compileAndGetDiagnostics({
+      "./sub.tsp": "namespace Foo; model FooModel {};",
+      "./main.tsp": 'import "./sub.tsp";\nusing Foo;',
+    });
+
+    expect(diags.length).toBeGreaterThanOrEqual(1);
+
+    const actions = await getCodeActions([diags[0]]);
+
+    // Should include individual fix but NOT "Fix all"
+    expect(actions.some((a) => a.kind === CodeActionKind.QuickFix)).toBe(true);
+    expect(actions.some((a) => a.data?.fixAllInFile !== undefined)).toBe(false);
+  });
+});
+
+describe("resolveCodeAction for Fix all", () => {
+  it("resolves 'Fix all: X' action applying all instances in the file", async () => {
+    const diags = await compileAndGetDiagnostics({
+      "./sub.tsp": "namespace Foo; model FooModel {};",
+      "./sub2.tsp": "namespace Bar; model BarModel {};",
+      "./main.tsp": 'import "./sub.tsp";\nimport "./sub2.tsp";\nusing Foo;\nusing Bar;',
+    });
+
+    expect(diags.length).toBeGreaterThanOrEqual(2);
+
+    const actions = await getCodeActions([diags[0]]);
+    const fixAllAction = actions.find((a) => a.data?.fixAllInFile !== undefined);
+    expect(fixAllAction).toBeDefined();
+
+    const resolved = await host.server.resolveCodeAction(fixAllAction!);
+    expect(resolved.edit?.documentChanges?.length).toBeGreaterThan(0);
+
+    // Should contain edits (both "using Foo" and "using Bar" removal)
+    const edits = resolved.edit!.documentChanges!.filter(
+      (c): c is { textDocument: any; edits: any[] } => "edits" in c,
+    );
+    const totalEdits = edits.reduce((sum, e) => sum + e.edits.length, 0);
+    expect(totalEdits).toBeGreaterThanOrEqual(2);
+  });
+});