[codex] fix diagnostic cache key collisions

apps/vscode-extension/src/diagnosticCacheKey.ts

@@ -0,0 +1,27 @@
+import type {
+  Diagnostic,
+  DiagnosticRelatedInformation,
+} from "vscode-languageserver-types";
+
+export function getDiagnosticCacheKey(diagnostic: Diagnostic): string {
+  return JSON.stringify({
+    message: diagnostic.message,
+    code: diagnostic.code,
+    range: diagnostic.range,
+    relatedInformation:
+      diagnostic.relatedInformation?.map(getRelatedInformationCacheKey) ?? [],
+  });
+}
+
+function getRelatedInformationCacheKey({
+  location,
+  message,
+}: DiagnosticRelatedInformation) {
+  return {
+    message,
+    location: {
+      uri: location.uri,
+      range: location.range,
+    },
+  };
+}

apps/vscode-extension/src/diagnostics.ts

@@ -19,6 +19,7 @@ import {
 } from "./formattedDiagnosticsStore";
 import { logger } from "./logger";
 import { enabledCommands } from "./commands/enabledCommands";
+import { getDiagnosticCacheKey } from "./diagnosticCacheKey";
 
 /**
  * The list of diagnostic sources that pretty-ts-errors supports
@@ -84,7 +85,7 @@ export function registerOnDidChangeDiagnostics(context: ExtensionContext) {
 const CACHE_SIZE_MAX = 100;
 
 /**
- * A local cache that maps TS diagnostics as `string` to their formatted `MarkdownString` counter part.
+ * A local cache that maps TS diagnostics to their formatted `MarkdownString` counter part.
  * @see https://github.com/yoavbls/pretty-ts-errors/pull/62
  *
  * One reason this cache is critical is because the TypeScript Language Features extension is very noisy and will constantly push all diagnostics for a file,
@@ -103,8 +104,9 @@ async function getFormattedDiagnostic(
   // formatDiagnosticForHover converts message based on LSP Diagnostic type, not VSCode Diagnostic type, so it can be used in other IDEs.
   // Here we convert VSCode Diagnostic to LSP Diagnostic to make formatDiagnosticForHover recognize it.
   const lspDiagnostic = converter.asDiagnostic(diagnostic);
+  const cacheKey = getDiagnosticCacheKey(lspDiagnostic);
 
-  let formattedMessage = cache.get(diagnostic.message);
+  let formattedMessage = cache.get(cacheKey);
   if (!formattedMessage) {
     const formattedDiagnostic = await prettifyDiagnosticForHover(lspDiagnostic);
     const markdownString = new MarkdownString(formattedDiagnostic);
@@ -117,7 +119,7 @@ async function getFormattedDiagnostic(
       const firstCacheKey = cache.keys().next().value!;
       cache.delete(firstCacheKey);
     }
-    cache.set(diagnostic.message, formattedMessage);
+    cache.set(cacheKey, formattedMessage);
   }
 
   return {

apps/vscode-extension/src/provider/webviewViewProvider.ts

@@ -19,6 +19,7 @@ import {
 } from "@pretty-ts-errors/vscode-formatter";
 import { SUPPORTED_LANGUAGE_IDS } from "../supportedLanguageIds";
 import { logger } from "../logger";
+import { getDiagnosticCacheKey } from "../diagnosticCacheKey";
 
 const NO_DIAGNOSTICS_MESSAGE =
   "Select code with an error to show the prettified diagnostic in this view.";
@@ -81,7 +82,7 @@ export function registerWebviewViewProvider(context: ExtensionContext) {
 async function diagnosticToItem(
   formattedDiagnostic: FormattedDiagnostic
 ): Promise<DiagnosticItem> {
-  const cacheKey = formattedDiagnostic.lspDiagnostic.message;
+  const cacheKey = getDiagnosticCacheKey(formattedDiagnostic.lspDiagnostic);
   let html = sidebarHtmlCache.get(cacheKey);
   if (!html) {
     html = await prettifyDiagnosticForSidebar(

apps/vscode-extension/src/test/suite/diagnosticCacheKey.test.ts

@@ -0,0 +1,53 @@
+import { strict as assert } from "node:assert";
+import type { Diagnostic } from "vscode-languageserver-types";
+import { getDiagnosticCacheKey } from "../../diagnosticCacheKey";
+
+suite("getDiagnosticCacheKey", () => {
+  test("distinguishes duplicate messages that link to different symbols", () => {
+    const firstKey = getDiagnosticCacheKey(
+      diagnosticWithRelatedInformation("file:///workspace/example.ts", 1)
+    );
+    const secondKey = getDiagnosticCacheKey(
+      diagnosticWithRelatedInformation("file:///workspace/other.ts", 1)
+    );
+
+    assert.notEqual(firstKey, secondKey);
+  });
+
+  test("distinguishes duplicate messages at different ranges", () => {
+    const firstKey = getDiagnosticCacheKey(
+      diagnosticWithRelatedInformation("file:///workspace/example.ts", 1)
+    );
+    const secondKey = getDiagnosticCacheKey(
+      diagnosticWithRelatedInformation("file:///workspace/example.ts", 8)
+    );
+
+    assert.notEqual(firstKey, secondKey);
+  });
+});
+
+function diagnosticWithRelatedInformation(
+  symbolUri: string,
+  startCharacter: number
+): Diagnostic {
+  return {
+    message: "Cannot find name 'Person'.",
+    code: 2304,
+    range: {
+      start: { line: 0, character: startCharacter },
+      end: { line: 0, character: startCharacter + 6 },
+    },
+    relatedInformation: [
+      {
+        message: "'Person' is declared here.",
+        location: {
+          uri: symbolUri,
+          range: {
+            start: { line: 3, character: 12 },
+            end: { line: 3, character: 18 },
+          },
+        },
+      },
+    ],
+  };
+}