1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
Tests
=====
We test the `webpack-stats-plugin` in all webpack browser version.
## Setup
To allow a multiple install scenario, we have multiple pseudo-packages and
configuration directories as follows:
```
test/{packages,scenarios}
├── webpack # Fake package to prevent node_modules flattening
├── webpack-cli # Fake package to prevent node_modules flattening
├── webpack1
├── webpack2
├── webpack3
├── webpack4
└── webpack5
```
where each `webpack<VERSION>` directory has a structure of:
```
test/packages/webpack1
├── index.js
└── package.json
test/scenarios/webpack1
└── webpack.config.js
```
where an independent `package.json` that has the desired `webpack`
(and `webpack-cli` for modern webpacks) version, e.g.:
```js
"dependencies": {
"webpack": "^1.15.0"
}
```
The `index.js` file in these directories is simply a re-export of the applicable
`webpack` CLI tool. We are then able to take a root `package.json` dependency on
each of these different versions like:
```js
"devDependencies": {
"webpack1": "file:test/packages/webpack1",
"webpack2": "file:test/packages/webpack2",
"webpack3": "file:test/packages/webpack3",
"webpack4": "file:test/packages/webpack4",
"webpack4": "file:test/packages/webpack5"
}
```
and we end up with **all** versions that we want!
**Side Note**: The `index.js` file is crafted carefully to account for
`node_modules` flattening performed by `yarn`. There are some complexities of
that omitted from this guide.
## Build
We then build files outside of git source to, e.g.:
```js
test/scenarios/webpack1
├── build
└── build2
```
We do this with a command that looks something like:
```sh
$ node node_modules/webpack5/index.js --config test/scenarios/webpack5/webpack.config.js
```
which importantly **must** change directory to our re-export file so that the
"detect a local webpack in `CWD/node_modules/.bin/webpack` scheme" doesn't take
over. The package in that location is only correct for **one** scenario and is
there because of webpack flattening.
## Tests
Once we have a build, we can do tests. We have a set of "expected" files that
are committed to source in:
```
test/expected/
├── build
│ ├── stats-custom.json
│ ├── stats-transform-custom-obj.json
│ ├── stats-transform.json
│ ├── stats-transform.md
│ └── stats.json
└── build2
└── stats-custom2.json
```
Our mocha tests in [func.spec.js](test/func.spec.js) first read in all of these expected files, then all of the build files from each of the `webpack<VERSION>` directories. We then have dynamic suites and tests to wrap this up and assert similarities.
We take a slight helping tool to regex replace any file hashes with the token `HASH` to get clean asserts.
Putting this all together, our steps are:
```sh
$ yarn run test:clean
$ yarn run test:build
$ yarn run test:run
```
or as a single command:
```sh
$ yarn run test
```
|
