Immutable.from (a reference to Immutable)

[ericclemmons]

This is a PR in response to #123, which allows users who follow & lint the condition that new precedes any capitalized, constructor function to use this library without littering their codebase with // eslint-disable-line comments:

http://eslint.org/docs/rules/new-cap

Before:

const thing = Immutable({}); // eslint-disable-line

After:

const thing = Immutable.from({});

I did a find/replace for = Immutable( to = Immutable.from in test/, and all 2108 tests still pass.

[ericclemmons]

However, new Immutable(...) would also satisfy this rule, but would fail 4 tests:

  2104 passing (8s)
  4 failing

What would you prefer? Immutable.from or supporting instantiation via new Immutable?

[rtfeldman]

new Immutable seems better, assuming it can be done in a way that doesn't break stuff (not sure which tests are failing, and whether it's the test's fault or the new logic's fault 😉 )

[ericclemmons]

@rtfeldman I agree. I'll post up more info. I'm a fan of new Immutable personally, but I know some people are completely anti-instantiation. But those people aren't the ones with the new-cap rule ;)

[ericclemmons]

Replacing the tests to use new Immutable yields:

  2104 passing (9s)
  4 failing

  1) Development build ImmutableArray returns only immutables when you call its reduce() method:

      AssertionError: expected '{}' to equal '0.10615249630063772'
      + expected - actual

      -{}
      +0.10615249630063772

      at Function.assert.strictEqual (node_modules/chai/lib/chai/interface/assert.js:178:32)
      at assertJsonEqual (test/TestUtils.js:13:12)
      at Object.assertImmutable (test/TestUtils.js:22:5)
      at Function.<anonymous> (test/ImmutableArray/test-compat.js:179:19)
      at Function.<anonymous> (test/TestUtils.js:121:18)
      at check (test/TestUtils.js:103:13)
      at test/TestUtils.js:117:7
      at Context.<anonymous> (test/ImmutableArray/test-compat.js:177:7)

  2) Development build ImmutableArray returns only immutables when you call its reduceRight() method:

      AssertionError: expected '{}' to equal '0.8079638944473118'
      + expected - actual

      -{}
      +0.8079638944473118

      at Function.assert.strictEqual (node_modules/chai/lib/chai/interface/assert.js:178:32)
      at assertJsonEqual (test/TestUtils.js:13:12)
      at Object.assertImmutable (test/TestUtils.js:22:5)
      at Function.<anonymous> (test/ImmutableArray/test-compat.js:179:19)
      at Function.<anonymous> (test/TestUtils.js:121:18)
      at check (test/TestUtils.js:103:13)
      at test/TestUtils.js:117:7
      at Context.<anonymous> (test/ImmutableArray/test-compat.js:177:7)

  3) Production build ImmutableArray returns only immutables when you call its reduce() method:

      AssertionError: expected '{}' to equal 'false'
      + expected - actual

      -{}
      +false

      at Function.assert.strictEqual (node_modules/chai/lib/chai/interface/assert.js:178:32)
      at assertJsonEqual (test/TestUtils.js:13:12)
      at Object.assertImmutable (test/TestUtils.js:22:5)
      at Function.<anonymous> (test/ImmutableArray/test-compat.js:179:19)
      at Function.<anonymous> (test/TestUtils.js:121:18)
      at check (test/TestUtils.js:103:13)
      at test/TestUtils.js:117:7
      at Context.<anonymous> (test/ImmutableArray/test-compat.js:177:7)

  4) Production build ImmutableArray returns only immutables when you call its reduceRight() method:

      AssertionError: expected '{}' to equal '""'
      + expected - actual

      -{}
      +""

      at Function.assert.strictEqual (node_modules/chai/lib/chai/interface/assert.js:178:32)
      at assertJsonEqual (test/TestUtils.js:13:12)
      at Object.assertImmutable (test/TestUtils.js:22:5)
      at Function.<anonymous> (test/ImmutableArray/test-compat.js:179:19)
      at Function.<anonymous> (test/TestUtils.js:121:18)
      at check (test/TestUtils.js:103:13)
      at test/TestUtils.js:117:7
      at Context.<anonymous> (test/ImmutableArray/test-compat.js:177:7)

From what I can tell it's the nonMutatingArrayMethods

[rtfeldman]

Oh right...if you use new, you have to get an object back; it can't return plain strings, numbers, null, etc. - all of which are currently supported (and passed through unchanged).

Let's just go with "from" after all haha

[ericclemmons]

Oh right! Travis is failing do to the Zuul testing (likely because my repo doesn't have the env vars yours does for testing).

Let me know what else you'd like @rtfeldman :)

[rtfeldman]

Looks good! Last request would be a quick mention in the README. 😸

[ericclemmons]

@rtfeldman Let me know if you'd like any other changes!

https://github.com/ericclemmons/seamless-immutable/blob/123-from/README.md#immutablefrom

[rtfeldman]

Lovely, thank you! :smile:

[rtfeldman]

@ericclemmons published as 6.1.0!