feat(ci): report webpack bundle size diffs on PRs

scripts/cra-bundle-stats-diff.py

@@ -0,0 +1,233 @@
+#!/usr/bin/env python
+
+
+from collections import namedtuple
+import json
+import os
+import sys
+import urllib2
+
+
+Bundle = namedtuple('Bundle' , 'seq bundleName totalBytes files')
+
+Diff = namedtuple('Diff', 'status path oldBytes newBytes isBigger diff')
+BundleDiff = namedtuple('BundleDiff', 'total files')
+
+
+class Status:
+    added    = 'added'
+    modified = 'modified'
+    deleted  = 'deleted'
+
+
+def humanize(value):
+    abbrevs = (
+        (1<<20, 'MB'),
+        (1<<10, 'kB'),
+        (1, 'bytes')
+    )
+    if value == 1:
+        return '1 byte'
+    for factor, suffix in abbrevs:
+        if value >= factor:
+            break
+    return '%d %s' % (value / factor, suffix)
+
+
+def readBundle(path):
+    bundles = []
+    with open(path) as f:
+        data = json.load(f)
+        for result in data['results']:
+            seq = os.path.basename(result['bundleName']).split('.')[0]
+            bundle = Bundle(
+                seq=seq,
+                bundleName=result['bundleName'],
+                totalBytes=result['totalBytes'],
+                files=result['files'])
+            bundles.append(bundle)
+    return bundles
+
+
+def printRow(diff, element):
+    if diff.status == Status.added:
+        status = '+'
+    elif diff.status == Status.modified:
+        status = 'M'
+    else:
+        status = '-'
+
+    sign = '+' if diff.isBigger else ''
+    ob = humanize(diff.oldBytes) if diff.oldBytes > 0 else ''
+    nb = humanize(diff.newBytes) if diff.newBytes > 0 else ''
+
+    return '''<tr>
+            <{element}>{status}</{element}>
+            <{element}>{path}</{element}>
+            <{element}>{ob}</{element}>
+            <{element}>{nb}</{element}>
+            <{element}>{sign}{diff}</{element}>
+        </tr>'''.format(
+            element=element,
+            status=status, path=diff.path,
+            ob=ob, nb=nb,
+            sign=sign, diff=humanize(diff.diff))
+
+
+def printBundleTable(diffs, element):
+    rows = []
+    for diff in diffs:
+        rows.append(printRow(diff, element))
+    return '<table><tbody>{body}</tbody></table>'.format(body='\n'.join(rows))
+
+
+def printBundleDiff(bundleDiff):
+    summary = printBundleTable([bundleDiff.total], 'th')
+    details = printBundleTable(bundleDiff.files, 'td')
+
+    return '''
+<details>
+    <summary>{summary}</summary>
+    {details}
+</details>
+'''.format(summary=summary, details=details)
+
+
+def makeDiff(path, oldBytes, newBytes):
+    if oldBytes > 0 and newBytes > 0:
+        status = Status.modified
+    elif oldBytes == 0:
+        status = Status.added
+    else:
+        status = Status.deleted
+    return Diff(
+        status=status,
+        path=path,
+        oldBytes=oldBytes,
+        newBytes=newBytes,
+        isBigger=newBytes > oldBytes,
+        diff=newBytes - oldBytes,
+    )
+
+
+def diffBundle(ba, bb):
+    filesDiffs = []
+    if ba.totalBytes != bb.totalBytes:
+        totalDiff = makeDiff(ba.bundleName, ba.totalBytes, bb.totalBytes)
+
+        for aFile in ba.files:
+            aSize = ba.files[aFile]['size']
+            if aFile in bb.files:
+                bSize = bb.files[aFile]['size']
+                if aSize != bSize:
+                    filesDiffs.append(makeDiff(aFile, aSize, bSize))
+            else:
+                filesDiffs.append(makeDiff(aFile, aSize, 0))
+
+        for bFile in bb.files:
+            bSize = bb.files[bFile]['size']
+            if bFile not in ba.files:
+                filesDiffs.append(makeDiff(bFile, 0, bSize))
+
+        return BundleDiff(total=totalDiff, files=filesDiffs)
+
+
+def summarize(diffs):
+    totalDiff = 0
+    for diff in diffs:
+        totalDiff += diff.total.diff
+    sign = '+' if totalDiff > 0 else ''
+    return '### Total diff: {sign}{totalDiff}'.format(
+        sign=sign, totalDiff=humanize(totalDiff))
+
+
+def postComment(diffs, pr, token, owner='prymitive', repo='karma'):
+    api = 'api.github.com'
+    uri = 'https://{api}/repos/{owner}/{repo}/issues/{pr}/comments'.format(
+        api=api, owner=owner, repo=repo, pr=pr)
+
+    rows = []
+    for diff in diffs:
+        rows.append(printBundleDiff(diff))
+    summary = summarize(diffs)
+    data = '*Webpack bundle size diff*\n{summary}\n{rows}'.format(
+        summary=summary, rows='\n'.join(rows))
+    encoded = json.dumps({'body': data})
+
+    req = urllib2.Request(uri)
+    req.add_header('Authorization', 'token %s' % token)
+    req.add_header("Content-Type", "application/json")
+    try:
+        response = urllib2.urlopen(req, encoded)
+    except Exception as e:
+        print("Request to '%s' failed: %s" % (uri, e))
+
+
+def diffBundles(a, b):
+    diffs = []
+    for ba in a:
+        found = False
+        for bb in b:
+            if ba.seq == bb.seq:
+                found = True
+                d = diffBundle(ba, bb)
+                if d:
+                    diffs.append(d)
+                break
+        if not found:
+            bb = Bundle(
+                    seq=ba.seq,
+                    bundleName=ba.bundleName,
+                    totalBytes=0,
+                    files={}
+            )
+            d = diffBundle(ba, bb)
+            if d:
+                diffs.append(d)
+
+    for bb in b:
+        found = False
+        for ba in a:
+            if bb.seq == ba.seq:
+                found = True
+        if not found:
+            ba = Bundle(
+                    seq=bb.seq,
+                    bundleName=bb.bundleName,
+                    totalBytes=0,
+                    files={}
+            )
+            d = diffBundle(ba, bb)
+            if d:
+                diffs.append(d)
+
+    diffs.sort(key=lambda x: x.total.newBytes, reverse=True)
+    return diffs
+
+
+if __name__ == '__main__':
+    if len(sys.argv) != 3:
+        print('Usage: PATH1 PATH2')
+        sys.exit(1)
+
+    token = os.getenv('GITHUB_TOKEN')
+    pr = os.getenv('TRAVIS_PULL_REQUEST')
+    bundleA = readBundle(sys.argv[1])
+    bundleB = readBundle(sys.argv[2])
+
+    if not token:
+        print('GITHUB_TOKEN env variable is missing')
+        sys.exit(1)
+    if not pr:
+        print('TRAVIS_PULL_REQUEST env variable is missing')
+        sys.exit(1)
+    if not bundleA or not bundleB:
+        print('Usage: PATH1 PATH2')
+        sys.exit(1)
+
+    diffs = diffBundles(bundleA, bundleB)
+    if diffs:
+        print('Found diffs, posting to GitHub')
+        postComment(diffs, pr, token)
+    else:
+        print('No diff found')