From 93d9df1c4c3e3f6485130ec2976876ab332d0ef2 Mon Sep 17 00:00:00 2001
From: joeduffy <joeduffy@acm.org>
Date: Sun, 12 Feb 2017 06:23:22 -0800
Subject: [PATCH] Issue a MuJS warning on unused dependencies

---
 tools/mujs/lib/compiler/transform.ts | 10 ++++++++++
 tools/mujs/lib/diag/context.ts       |  8 ++++++++
 2 files changed, 18 insertions(+)

diff --git a/tools/mujs/lib/compiler/transform.ts b/tools/mujs/lib/compiler/transform.ts
index 627bdbb03..ebb44cee7 100644
--- a/tools/mujs/lib/compiler/transform.ts
+++ b/tools/mujs/lib/compiler/transform.ts
@@ -275,6 +275,16 @@ export class Transformer {
                 }
             }
 
+            // Also warn about dependency packages that weren't actually used.
+            if (this.pkg.dependencies) {
+                for (let dep of Object.keys(this.pkg.dependencies)) {
+                    if (!this.currentPackageDependencies.has(dep)) {
+                        this.diagnostics.push(this.dctx.newUnusedDependencyWarning(dep));
+                    }
+                }
+            }
+
+
             // Now create a new package object.
             return <TransformResult>{
                 diagnostics: this.diagnostics,
diff --git a/tools/mujs/lib/diag/context.ts b/tools/mujs/lib/diag/context.ts
index 6e2e2e306..f5a33908a 100644
--- a/tools/mujs/lib/diag/context.ts
+++ b/tools/mujs/lib/diag/context.ts
@@ -221,6 +221,14 @@ export class Context {
         };
     }
 
+    public newUnusedDependencyWarning(pkg: tokens.PackageToken): Diagnostic {
+        return {
+            category: DiagnosticCategory.Warning,
+            code:     4,
+            message:  `Package '${pkg}' was declared as a dependency but not used`,
+        };
+    }
+
     public newAsyncNotSupportedError(node: ts.Node): Diagnostic {
         return {
             category: DiagnosticCategory.Error,