Use Function("return this") to get global?

[creatorrr]

Underscore currently breaks in 'strict' mode while trying to access properties on the global object. The global object is being set using the (function(root) { ... })(this) pattern. However, in this case, root remains undefined and hence the issue.

Using the Function("return this")() pattern instead alleviates the issue, though arguably ugly. Thoughts?

Steps to reproduce: Import underscore in a babel-jest test harness. (uses strict mode)

[jridgewell]

Would be better to just create a root object on L12.

  var root = this || {};

[jashkenas]

Underscore doesn't use strict mode.

[jridgewell]

It's not an issue of Underscore using strict mode, but the new ES6 module loaders forcing strict mode.

[jashkenas]

Seriously? Strict mode is enforced now in "real" ES6? Or is this just "polyfill" module loaders being zealous?

[jashkenas]

http://people.mozilla.org/~jorendorff/es6-draft.html#sec-strict-mode-code

Ugh.

Is this going to play nice with _.template?

[jridgewell]

It's not strict mode exactly. The ES6 spec says that this is undefined for module contexts.

[jridgewell]

http://people.mozilla.org/~jorendorff/es6-draft.html#sec-strict-mode-code

I stand corrected, it's always strict mode.

[megawac]

Can we replace this with self? I'm pretty sure that should work with all browsers I've ever used

[megawac]

^ That would also add support for loading underscore in webworkers

[creatorrr]

@jashkenas jest doesn't play well with loading underscore either.

[creatorrr]

Also, this issue affects Backbone as well. Relevant issue: jashkenas/backbone#3566

[creatorrr]

@megawac self won't work in node or iojs.

[megawac]

See pull
On Apr 16, 2015 8:13 AM, "Diwank Singh Tomer" notifications@github.com
wrote:

@megawac https://github.com/megawac self won't work in node or iojs.

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#2152 (comment)
.

[fangmobile]

ran into this when using babel-jest as scriptPreprocessor. Any idea? 1.8.3

  "dependencies": {
    "react-native": "^0.12.0",
    "react-native-animatable": "^0.1.0",
    "react-native-webintent": "^1.0.2"
  },
  "devDependencies": {
    "babel-jest": "*",
    "jest-cli": "^0.7.0"
  },
  "jest": {
    "collectCoverage": true,
    "rootDir": "./",        (I also used "", but same thing)
    "scriptPreprocessor": "<rootDir>/node_modules/babel-jest",
    "testFileExtensions": ["es6", "js"],
    "moduleFileExtensions": ["js", "json", "es6"]
  }

● Runtime Error
TypeError: /Users/yourname/Proj/ReactNativeExperiment/__tests__/test2-test.js: /Proj/src/components/assets/multiSelect.js:Proj/lib/underscore.js: Cannot read property '_' of undefined
    at Proj/lib/underscore.js:15:32
    at Object.<anonymous> (Proj/src/lib/underscore.js:1548:1)
    at Object.runContentWithLocalBindings (/Proj/node_modules/jest-cli/src/lib/utils.js:394:17)
    at Loader._execModule (/Proj/node_modules/jest-cli/src/HasteModuleLoader/HasteModuleLoader.js:234:11)
    at Loader.requireModule (/Prou/node_modules/jest-cli/src/HasteModuleLoader/HasteModuleLoader.js:845:14)
    at Loader.requireModuleOrMock /Prou/node_modules/jest-cli/src/HasteModuleLoader/HasteModuleLoader.js:875:19)
    at Object.<anonymous> (Proj/src/components/assets/multiSelect.js:9:45)
    at Object.runContentWithLocalBindings (/Proj/node_modules/jest-cli/src/lib/utils.js:394:17)
    at Loader._execModule (/Proj/node_modules/jest-cli/src/HasteModuleLoader/HasteModuleLoader.js:234:11)
    at Loader.requireModule (Proj/node_modules/jest-cli/src/HasteModuleLoader/HasteModuleLoader.js:845:14)
    at Loader.requireModuleOrMock (Proj/node_modules/jest-cli/src/HasteModuleLoader/HasteModuleLoader.js:875:19)
    at Object.<anonymous> (//Proj/__tests__/test2-test.js:4:19)
    at Object.runContentWithLocalBindings (/Proj/node_modules/jest-cli/src/lib/utils.js:394:17)
    at Loader._execModule /Proj/node_modules/jest-cli/src/HasteModuleLoader/HasteModuleLoader.js:234:11)
    at Loader.requireModule (/Proj//node_modules/jest-cli/src/HasteModuleLoader/HasteModuleLoader.js:845:14)
    at jasmineTestRunner (/Proj/node_modules/jest-cli/src/jasmineTestRunner/jasmineTestRunner.js:264:16)
    at /Proj/node_modules/jest-cli/src/TestRunner.js:379:14