Document testing #538

gaearon · 2016-09-01T21:35:51Z

Coming soon!

kentcdodds · 2016-09-01T21:47:35Z

template/README.md

+
+### Command Line Interface
+
+When you run `npm test`, Jest will launch in the watch mode. Every time you save a file, it will re-run the tests, just like `npm start` recompiles the code.


I would recommend against watch mode being the default. Many CI systems will run npm test by default. In my experience, it's more common to have npm test run the tests once (with --coverage) and have a watch:test script.

Oh dang. I just saw the note about how jest is smart and wont watch on CI... That's a super feature!

Yeah, that's something we do in react-scripts as suggested by @ForbesLindesay but maybe Jest could do that by default! cc @cpojer

Pretty amazing what you can do when you just forward npm scripts onto your own binary :)

Dan: wanna send a PR for that? I'm happy to ship that as a default. As we expand interactive watch, there are probably few reasons to not use it as a default.

kentcdodds · 2016-09-01T21:51:37Z

template/README.md

+
+### Writing Tests
+
+To create tests, add `it()` blocks with the name of the test and its code. You may optionally wrap them in `describe()` blocks for logical grouping but this it not required.


I might even add (nor is it recommended). Here's why I feel that way..

kentcdodds · 2016-09-01T22:03:13Z

template/README.md

+  // ...
+  "scripts": {
+    // ...
+    "test": "react-scripts test --env=jsdom"


That's interesting! I haven't followed CRA too closely, but this appears to be the first instance of anything that resembles config. Is this the decided upon method of config? Is this something to be concerned about? I realize that this is a pretty useful optimization. Just wanted to call it out.

It’s mostly there to stick out so people are incentivized to figure out ways to test their stuff without jsdom. 😉

In the future, as mentioned, we’ll be recommending snapshot testing, and when it becomes the default test we ship, we’ll remove env=jsdom from the default test script.

kentcdodds · 2016-09-01T22:06:31Z

This is fantastic 👏

cpojer · 2016-09-01T23:10:23Z

README.md

@@ -144,7 +151,8 @@ Currently it is a thin layer on top of many amazing community projects, such as:
 * [Babel](http://babeljs.io/) with ES6 and extensions used by Facebook (JSX, [object spread](https://github.com/sebmarkbage/ecmascript-rest-spread/commits/master), [class properties](https://github.com/jeffmo/es-class-public-fields))
 * [Autoprefixer](https://github.com/postcss/autoprefixer)
 * [ESLint](http://eslint.org/)
-* and more.
+* [Jest](http://facebook.github.io/jest) (it’s [not bad anymore!](http://facebook.github.io/jest/blog/2016/09/01/jest-15.html))


haha, I'm not sure what to think about this.

haha, yeah, perhaps changing the wording to be more kind and positive. Afterall, real people worked hard on Jest before too.

well, the thing is, most people that will read this have never heard of Jest and this gives them a negative impression. The people that knew about Jest being terrible are the ones that used React years ago already.

Could also say "Jest" and highlight the two latest release blog posts with explanation of great features.

Removed it 😄

cpojer · 2016-09-01T23:22:19Z

template/README.md

+
+>Note: this feature is available with `[email protected]` and higher.
+
+Create React App uses [Jest](https://facebook.github.io/jest/) as its test runner. To prepare for this integration, we did a [major revamp](https://facebook.github.io/jest/blog/2016/09/01/jest-15.html) of Jest so if you heard bad things about it, give it another try.


Here too. "We did a major revamp to improve new user experience"?

Did we not? “Jest is bad” is well and alive, no need to look further than the recent issue. I do think we need to address this concern in text. I don’t think it makes us look bad, just honest about past problems and our willingness to solve them.

yeah that makes sense. Can we maybe say "The only resemblance of Jest with the test framework from a year ago is its name?" That sounds more uplifting. I just wanna avoid giving people a bad impression if they haven't even heard about Jest before.

Let’s discuss in a follow up PR if you’d like to make a pass over this. But as you know, it’s better to under-promise and over-deliver. I would give it a few months and then revisit when the perception is turned around thanks to word of mouth.

trabianmatt · 2016-09-02T00:36:09Z

template/README.md

+});
+```
+
+This test mounts a component and makes sure that it didn’t throw during rendering. Tests like this provide a lot value with very little effort so they are great as a starting point, and this is the test you will find in `src/App.test.js`.


"lot of value"

trevordmiller · 2016-09-02T06:12:09Z

Great stuff. Looking forward to jsdom getting ripped out and Node only tests + snapshots becoming the default 💪

* Document testing * Update README.md * Update README.md * Clarify our recommendations on testing * Okay, that was too much. :-) * Add a few more things

Document testing

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Clarify our recommendations on testing

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Okay, that was too much. :-)

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Add a few more things

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Document testing #538

Document testing #538

gaearon commented Sep 1, 2016

kentcdodds Sep 1, 2016 •

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trevordmiller commented Sep 2, 2016


		### Command Line Interface

		When you run `npm test`, Jest will launch in the watch mode. Every time you save a file, it will re-run the tests, just like `npm start` recompiles the code.


		### Writing Tests

		To create tests, add `it()` blocks with the name of the test and its code. You may optionally wrap them in `describe()` blocks for logical grouping but this it not required.


		>Note: this feature is available with `[email protected]` and higher.

		Create React App uses [Jest](https://facebook.github.io/jest/) as its test runner. To prepare for this integration, we did a [major revamp](https://facebook.github.io/jest/blog/2016/09/01/jest-15.html) of Jest so if you heard bad things about it, give it another try.

Document testing #538

Document testing #538

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gaearon commented Sep 1, 2016

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kentcdodds commented Sep 1, 2016

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trevordmiller commented Sep 2, 2016

kentcdodds Sep 1, 2016 •

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