fix: move vm.runInDebugContext to constructor (#509)

to support bundlers, and more closely match the pattern of other code in
the project we create the debug context in the constructor rather than
in the file.

fixes /issues/503

package.json

@@ -57,6 +57,7 @@
     "once": "^1.4.0",
     "post-install-check": "0.0.1",
     "proxyquire": "^2.0.0",
+    "require-inject": "^1.4.3",
     "rimraf": "^2.6.2",
     "source-map-support": "^0.5.6",
     "tmp": "0.0.33",

src/agent/state/legacy-state.ts

@@ -29,9 +29,7 @@ import * as v8 from '../../types/v8';
 import * as stackdriver from '../../types/stackdriver';
 import {ResolvedDebugAgentConfig} from '../config';
 
-// TODO: Determine if `ScopeType` should be named `scopeType`.
-// tslint:disable-next-line:variable-name
-const ScopeType = vm.runInDebugContext('ScopeType');
+
 const assert = debugAssert(!!process.env.CLOUD_DEBUG_ASSERTIONS);
 
 // Error message indices into the resolved variable table.
@@ -79,7 +77,7 @@ class StateResolver {
   private messageTable: stackdriver.Variable[];
   private resolvedVariableTable: stackdriver.Variable[];
   private rawVariableTable: Array<v8.ValueMirror|null>;
-
+  private scopeType: {Global: {}, Script: {}, Closure: {}, Local: {}};
   /**
    * @param {!Object} execState
    * @param {Array<string>} expressions
@@ -127,6 +125,8 @@ class StateResolver {
     this.rawVariableTable = this.messageTable.map(() => {
       return null;
     });
+
+    this.scopeType = vm.runInDebugContext('ScopeType');
   }
 
 
@@ -382,17 +382,17 @@ class StateResolver {
     // For top-level breakpoints: [local, script, global]
     // Other: [..., closure (module IIFE), script, global]
     assert.ok(count >= 3);
-    assert.strictEqual(allScopes[count - 1].scopeType(), ScopeType.Global);
-    assert.strictEqual(allScopes[count - 2].scopeType(), ScopeType.Script);
+    assert.strictEqual(allScopes[count - 1].scopeType(), self.scopeType.Global);
+    assert.strictEqual(allScopes[count - 2].scopeType(), self.scopeType.Script);
 
     // We find the top-level (module global) variable pollute the local
     // variables we omit them by default, unless the breakpoint itself is
     // top-level. The last two scopes are always omitted.
     let scopes: v8.ScopeMirror[];
-    if (allScopes[count - 3].scopeType() === ScopeType.Closure) {
+    if (allScopes[count - 3].scopeType() === self.scopeType.Closure) {
       scopes = allScopes.slice(0, -3);
     } else {
-      assert.ok(allScopes[count - 3].scopeType() === ScopeType.Local);
+      assert.ok(allScopes[count - 3].scopeType() === self.scopeType.Local);
       scopes = allScopes.slice(0, -2);
     }
 

test/test-state.ts

@@ -39,4 +39,12 @@ describeFn('state', () => {
       state.testAssert();
     });
   });
+
+  it('should not throw if vm is not an object', () => {
+    // test for
+    // https://github.com/GoogleCloudPlatform/cloud-debug-nodejs/issues/503
+    const inject = require('require-inject');
+    const state = inject('../src/agent/state/legacy-state', {vm: false});
+    assert.ok(state);
+  });
 });