From 382785a5282f6d49dae0f6af483c8acdaf89ed78 Mon Sep 17 00:00:00 2001
From: Andy <anhans@microsoft.com>
Date: Tue, 8 Aug 2017 07:54:08 -0700
Subject: [PATCH] Fix logging of module resolution errors (#17144)

---
 src/compiler/moduleNameResolver.ts    | 2 +-
 src/harness/harnessLanguageService.ts | 2 +-
 src/server/project.ts                 | 3 ++-
 src/server/server.ts                  | 2 --
 src/server/types.ts                   | 2 +-
 5 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/compiler/moduleNameResolver.ts b/src/compiler/moduleNameResolver.ts
index 513c741ba09..be867db9743 100644
--- a/src/compiler/moduleNameResolver.ts
+++ b/src/compiler/moduleNameResolver.ts
@@ -678,7 +678,7 @@ namespace ts {
         const { resolvedModule, failedLookupLocations } =
             nodeModuleNameResolverWorker(moduleName, initialDir, { moduleResolution: ts.ModuleResolutionKind.NodeJs, allowJs: true }, host, /*cache*/ undefined, /*jsOnly*/ true);
         if (!resolvedModule) {
-            throw new Error(`Could not resolve JS module ${moduleName} starting at ${initialDir}. Looked in: ${failedLookupLocations.join(", ")}`);
+            throw new Error(`Could not resolve JS module '${moduleName}' starting at '${initialDir}'. Looked in: ${failedLookupLocations.join(", ")}`);
         }
         return resolvedModule.resolvedFileName;
     }
diff --git a/src/harness/harnessLanguageService.ts b/src/harness/harnessLanguageService.ts
index c604b224656..994ebe67e0c 100644
--- a/src/harness/harnessLanguageService.ts
+++ b/src/harness/harnessLanguageService.ts
@@ -795,7 +795,7 @@ namespace Harness.LanguageService {
                 default:
                     return {
                         module: undefined,
-                        error: "Could not resolve module"
+                        error: new Error("Could not resolve module")
                     };
             }
 
diff --git a/src/server/project.ts b/src/server/project.ts
index 524b6c4d28d..5a92e6505e0 100644
--- a/src/server/project.ts
+++ b/src/server/project.ts
@@ -170,7 +170,8 @@ namespace ts.server {
             log(`Loading ${moduleName} from ${initialDir} (resolved to ${resolvedPath})`);
             const result = host.require(resolvedPath, moduleName);
             if (result.error) {
-                log(`Failed to load module: ${JSON.stringify(result.error)}`);
+                const err = result.error.stack || result.error.message || JSON.stringify(result.error);
+                log(`Failed to load module '${moduleName}': ${err}`);
                 return undefined;
             }
             return result.module;
diff --git a/src/server/server.ts b/src/server/server.ts
index b72cc2f5a81..d0044153b91 100644
--- a/src/server/server.ts
+++ b/src/server/server.ts
@@ -116,8 +116,6 @@ namespace ts.server {
         birthtime: Date;
     }
 
-    type RequireResult = { module: {}, error: undefined } | { module: undefined, error: {} };
-
     const readline: {
         createInterface(options: ReadLineOptions): NodeJS.EventEmitter;
     } = require("readline");
diff --git a/src/server/types.ts b/src/server/types.ts
index 07b94fe827e..4fc4356a4a9 100644
--- a/src/server/types.ts
+++ b/src/server/types.ts
@@ -9,7 +9,7 @@ declare namespace ts.server {
         data: any;
     }
 
-    type RequireResult = { module: {}, error: undefined } | { module: undefined, error: {} };
+    type RequireResult = { module: {}, error: undefined } | { module: undefined, error: { stack?: string, message?: string } };
     export interface ServerHost extends System {
         setTimeout(callback: (...args: any[]) => void, ms: number, ...args: any[]): any;
         clearTimeout(timeoutId: any): void;