Use empty object for invalid package json contents instead of undefined

src/services/utilities.ts

@@ -2218,22 +2218,22 @@ namespace ts {
         type PackageJsonRaw = Record<typeof dependencyKeys[number], Record<string, string> | undefined>;
         const dependencyKeys = ["dependencies", "devDependencies", "optionalDependencies", "peerDependencies"] as const;
         const stringContent = host.readFile(fileName);
-        const content = stringContent && tryParseJson(stringContent) as PackageJsonRaw;
-        if (!content) {
-            return undefined;
-        }
+        if (!stringContent) return undefined;
 
+        const content = tryParseJson(stringContent) as PackageJsonRaw;
         const info: Pick<PackageJsonInfo, typeof dependencyKeys[number]> = {};
-        for (const key of dependencyKeys) {
-            const dependencies = content[key];
-            if (!dependencies) {
-                continue;
-            }
-            const dependencyMap = createMap<string>();
-            for (const packageName in dependencies) {
-                dependencyMap.set(packageName, dependencies[packageName]);
+        if (content) {
+            for (const key of dependencyKeys) {
+                const dependencies = content[key];
+                if (!dependencies) {
+                    continue;
+                }
+                const dependencyMap = createMap<string>();
+                for (const packageName in dependencies) {
+                    dependencyMap.set(packageName, dependencies[packageName]);
+                }
+                info[key] = dependencyMap;
             }
-            info[key] = dependencyMap;
         }
 
         const dependencyGroups = [

src/testRunner/unittests/tsserver/packageJsonInfo.ts

@@ -71,6 +71,18 @@ namespace ts.projectSystem {
             assert.lengthOf(project.getPackageJsonsVisibleToFile("/a.ts" as Path), 1);
             assert.lengthOf(project.getPackageJsonsVisibleToFile("/src/b.ts" as Path), 2);
         });
+
+        it("handles errors in json parsing of package.json", () => {
+            const packageJsonContent = `{ "mod" }`;
+            const { project } = setup([tsConfig, { path: packageJson.path, content: packageJsonContent }]);
+            project.getPackageJsonsVisibleToFile("/src/whatever/blah.ts" as Path);
+            const packageJsonInfo = project.packageJsonCache.getInDirectory("/" as Path)!;
+            assert.isObject(packageJsonInfo);
+            assert.isUndefined(packageJsonInfo.dependencies);
+            assert.isUndefined(packageJsonInfo.devDependencies);
+            assert.isUndefined(packageJsonInfo.peerDependencies);
+            assert.isUndefined(packageJsonInfo.optionalDependencies);
+        });
     });
 
     function setup(files: readonly File[] = [tsConfig, packageJson]) {

tests/cases/fourslash/server/importSuggestionsCache_invalidPackageJson.ts

@@ -0,0 +1,57 @@
+/// <reference path="../fourslash.ts" />
+
+// @Filename: /jsconfig.json
+////{
+////  "compilerOptions": {
+////    "module": "commonjs",
+////  },
+////}
+
+// @Filename: /node_modules/@types/node/index.d.ts
+////declare module 'fs' {
+////  export function readFile(): void;
+////}
+////declare module 'util' {
+////  export function promisify(): void;
+////}
+
+// @Filename: /package.json
+////{ "mod" }
+
+// @Filename: /a.js
+////
+////readF/**/
+
+verifyExcludes("readFile");
+edit.replaceLine(0, "import { promisify } from 'util';");
+verifyIncludes("readFile");
+edit.deleteLine(0);
+verifyExcludes("readFile");
+
+function verifyIncludes(name: string) {
+  goTo.marker("");
+  verify.completions({
+      includes: {
+          name,
+          source: "fs",
+          hasAction: true,
+          sortText: completion.SortText.AutoImportSuggestions,
+      },
+      preferences: {
+          includeCompletionsForModuleExports: true,
+          includeInsertTextCompletions: true,
+      },
+  });
+}
+
+function verifyExcludes(name: string) {
+  goTo.marker("");
+  verify.completions({
+      excludes: name,
+      preferences: {
+          includeCompletionsForModuleExports: true,
+          includeInsertTextCompletions: true,
+      },
+  });
+}
+