From 0b9b321b0c21cca7b9988490ecc80edf54591ac4 Mon Sep 17 00:00:00 2001
From: Andrew Branch <andrew@wheream.io>
Date: Thu, 6 Aug 2020 09:34:46 -0700
Subject: [PATCH] Handle empty package.json files

---
 src/server/editorServices.ts                    | 15 +++++++--------
 src/server/packageJsonCache.ts                  |  8 +++-----
 src/services/utilities.ts                       |  4 +---
 .../unittests/tsserver/packageJsonInfo.ts       | 17 +++++++++++++++++
 4 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index dc94d3b201436..a86e383d7b93a 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -3774,12 +3774,10 @@ namespace ts.server {
         /*@internal*/
         getPackageJsonsVisibleToFile(fileName: string, rootDir?: string): readonly PackageJsonInfo[] {
             const packageJsonCache = this.packageJsonCache;
-            const watchPackageJsonFile = this.watchPackageJsonFile.bind(this);
-            const toPath = this.toPath.bind(this);
-            const rootPath = rootDir && toPath(rootDir);
-            const filePath = toPath(fileName);
+            const rootPath = rootDir && this.toPath(rootDir);
+            const filePath = this.toPath(fileName);
             const result: PackageJsonInfo[] = [];
-            forEachAncestorDirectory(getDirectoryPath(filePath), function processDirectory(directory): boolean | undefined {
+            const processDirectory = (directory: Path): boolean | undefined => {
                 switch (packageJsonCache.directoryHasPackageJson(directory)) {
                     // Sync and check same directory again
                     case Ternary.Maybe:
@@ -3788,15 +3786,16 @@ namespace ts.server {
                     // Check package.json
                     case Ternary.True:
                         const packageJsonFileName = combinePaths(directory, "package.json");
-                        watchPackageJsonFile(packageJsonFileName);
+                        this.watchPackageJsonFile(packageJsonFileName as Path);
                         const info = packageJsonCache.getInDirectory(directory);
                         if (info) result.push(info);
                 }
-                if (rootPath && rootPath === toPath(directory)) {
+                if (rootPath && rootPath === this.toPath(directory)) {
                     return true;
                 }
-            });
+            };
 
+            forEachAncestorDirectory(getDirectoryPath(filePath), processDirectory);
             return result;
         }
 
diff --git a/src/server/packageJsonCache.ts b/src/server/packageJsonCache.ts
index 8c09ebda2c4d6..3aa6129430a53 100644
--- a/src/server/packageJsonCache.ts
+++ b/src/server/packageJsonCache.ts
@@ -42,11 +42,9 @@ namespace ts.server {
         };
 
         function addOrUpdate(fileName: Path) {
-            const packageJsonInfo = createPackageJsonInfo(fileName, host.host);
-            if (packageJsonInfo !== undefined) {
-                packageJsons.set(fileName, packageJsonInfo);
-                directoriesWithoutPackageJson.delete(getDirectoryPath(fileName));
-            }
+            const packageJsonInfo = Debug.checkDefined(createPackageJsonInfo(fileName, host.host));
+            packageJsons.set(fileName, packageJsonInfo);
+            directoriesWithoutPackageJson.delete(getDirectoryPath(fileName));
         }
 
         function directoryHasPackageJson(directory: Path) {
diff --git a/src/services/utilities.ts b/src/services/utilities.ts
index c11c65d076dd6..baa70bf1df84f 100644
--- a/src/services/utilities.ts
+++ b/src/services/utilities.ts
@@ -2735,9 +2735,7 @@ 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);
-        if (!stringContent) return undefined;
-
+        const stringContent = host.readFile(fileName) || "";
         const content = tryParseJson(stringContent) as PackageJsonRaw | undefined;
         const info: Pick<PackageJsonInfo, typeof dependencyKeys[number]> = {};
         if (content) {
diff --git a/src/testRunner/unittests/tsserver/packageJsonInfo.ts b/src/testRunner/unittests/tsserver/packageJsonInfo.ts
index efc977a335c92..b931d984c1275 100644
--- a/src/testRunner/unittests/tsserver/packageJsonInfo.ts
+++ b/src/testRunner/unittests/tsserver/packageJsonInfo.ts
@@ -82,6 +82,23 @@ namespace ts.projectSystem {
             assert.ok(packageJsonInfo2.peerDependencies);
             assert.ok(packageJsonInfo2.optionalDependencies);
         });
+
+        it("handles empty package.json", () => {
+            const packageJsonContent = "";
+            const { projectService, host } = setup([tsConfig, { path: packageJson.path, content: packageJsonContent }]);
+            projectService.getPackageJsonsVisibleToFile("/src/whatever/blah.ts" as Path);
+            const packageJsonInfo = projectService.packageJsonCache.getInDirectory("/" as Path)!;
+            assert.isFalse(packageJsonInfo.parseable);
+
+            host.writeFile(packageJson.path, packageJson.content);
+            projectService.getPackageJsonsVisibleToFile("/src/whatever/blah.ts" as Path);
+            const packageJsonInfo2 = projectService.packageJsonCache.getInDirectory("/" as Path)!;
+            assert.ok(packageJsonInfo2);
+            assert.ok(packageJsonInfo2.dependencies);
+            assert.ok(packageJsonInfo2.devDependencies);
+            assert.ok(packageJsonInfo2.peerDependencies);
+            assert.ok(packageJsonInfo2.optionalDependencies);
+        });
     });
 
     function setup(files: readonly File[] = [tsConfig, packageJson]) {