codekingpro/portable-devtools

1const pacote = require('pacote')
2
3const formatDiff = require('./format-diff.js')
4const getTarball = require('./tarball.js')
5const untar = require('./untar.js')
6
7// TODO: we test this condition in the diff command
8// so this error probably doesnt need to be here. Or
9// if it does we should figure out a standard code
10// so we can catch it in the cli and display it consistently
11const argsError = () =>
12  Object.assign(
13    new TypeError('libnpmdiff needs two arguments to compare'),
14    { code: 'EDIFFARGS' }
15  )
16const diff = async (specs, opts = {}) => {
17  if (specs.length !== 2) {
18    throw argsError()
19  }
20
21  const [
22    aManifest,
23    bManifest,
24  ] =
25    await Promise.all(specs.map(spec => pacote.manifest(spec, {
26      ...opts,
27      _isRoot: true,
28    })))
29
30  const versions = {
31    a: aManifest.version,
32    b: bManifest.version,
33  }
34
35  // fetches tarball using pacote
36  const [a, b] = await Promise.all([
37    getTarball(aManifest, opts),
38    getTarball(bManifest, opts),
39  ])
40
41  // read all files
42  // populates `files` and `refs`
43  const {
44    files,
45    refs,
46  } = await untar([
47    {
48      prefix: 'a/',
49      item: a,
50    },
51    {
52      prefix: 'b/',
53      item: b,
54    },
55  ], opts)
56
57  return formatDiff({
58    files,
59    opts,
60    refs,
61    versions,
62  })
63}
64
65module.exports = diff
66