fix(config): allow .npmrc config to supersede yarn defaults

__tests__/registries/yarn-registry.js

@@ -0,0 +1,100 @@
+/* @flow */
+
+import YarnRegistry from '../../src/registries/yarn-registry.js';
+import {BufferReporter} from '../../src/reporters/index.js';
+import {YARN_REGISTRY} from '../../src/constants.js';
+
+function createMocks(): Object {
+  const mockRequestManager = {
+    request: jest.fn(),
+  };
+
+  const mockRegistries = {
+    npm: {
+      getOption(key): mixed {
+        return this.config[key];
+      },
+    },
+    yarn: {},
+  };
+
+  const reporter = new BufferReporter({verbose: true});
+
+  return {
+    mockRequestManager,
+    mockRegistries,
+    reporter,
+  };
+}
+
+describe('yarn registry getOption', () => {
+  test('that getOption falls back to npm if the key is defined as a npm config and also is a yarn default', () => {
+    const {mockRequestManager, mockRegistries, reporter} = createMocks();
+    const yarnRegistry = new YarnRegistry('.', mockRegistries, mockRequestManager, reporter);
+
+    mockRegistries.npm.config = {
+      registry: 'npm:custom-registry',
+    };
+
+    yarnRegistry.config = {
+      registry: YARN_REGISTRY,
+    };
+
+    yarnRegistry.configWithoutDefaults = {};
+
+    expect(yarnRegistry.getOption('registry')).toEqual('npm:custom-registry');
+  });
+
+  test('that getOption will respect custom yarn options over npm', () => {
+    const {mockRequestManager, mockRegistries, reporter} = createMocks();
+    const yarnRegistry = new YarnRegistry('.', mockRegistries, mockRequestManager, reporter);
+
+    mockRegistries.npm.config = {
+      registry: 'npm:custom-registry',
+    };
+
+    yarnRegistry.config = {
+      registry: 'yarn:custom-registry',
+    };
+
+    yarnRegistry.configWithoutDefaults = {
+      registry: 'yarn:custom-registry',
+    };
+
+    expect(yarnRegistry.getOption('registry')).toEqual('yarn:custom-registry');
+  });
+
+  test('that if a option is not defined on either yarn or npm we use yarns default', () => {
+    const {mockRequestManager, mockRegistries, reporter} = createMocks();
+    const yarnRegistry = new YarnRegistry('.', mockRegistries, mockRequestManager, reporter);
+
+    mockRegistries.npm.config = {};
+
+    yarnRegistry.config = {
+      registry: YARN_REGISTRY,
+    };
+
+    yarnRegistry.configWithoutDefaults = {};
+
+    expect(yarnRegistry.getOption('registry')).toEqual(YARN_REGISTRY);
+  });
+
+  test('that if the yarn config value is the same as the default it will be used', () => {
+    const {mockRequestManager, mockRegistries, reporter} = createMocks();
+    const yarnRegistry = new YarnRegistry('.', mockRegistries, mockRequestManager, reporter);
+
+    mockRegistries.npm.config = {
+      registry: 'npm:registry',
+    };
+
+    yarnRegistry.config = {
+      registry: YARN_REGISTRY,
+    };
+
+    yarnRegistry.configWithoutDefaults = {
+      registry: YARN_REGISTRY,
+    };
+
+    expect(yarnRegistry.getOption('registry')).toEqual(YARN_REGISTRY);
+  });
+});

src/registries/yarn-registry.js

@@ -51,9 +51,10 @@ export default class YarnRegistry extends NpmRegistry {
 
   homeConfigLoc: string;
   homeConfig: Object;
+  configWithoutDefaults: Object;
 
   getOption(key: string): mixed {
-    let val = this.config[key];
+    let val = this.configWithoutDefaults[key];
 
     // if this isn't set in a yarn config, then use npm
     if (typeof val === 'undefined') {
@@ -66,7 +67,7 @@ export default class YarnRegistry extends NpmRegistry {
 
     // if this isn't set in a yarn config or npm config, then use the default (or undefined)
     if (typeof val === 'undefined') {
-      val = DEFAULTS[key];
+      val = this.config[key];
     }
 
     return val;
@@ -102,6 +103,7 @@ export default class YarnRegistry extends NpmRegistry {
     }
 
     // default yarn config
+    this.configWithoutDefaults = Object.assign({}, this.config);
     this.config = Object.assign({}, DEFAULTS, this.config);
   }