rules: add metadata-end rule

This rule verifies that there should be no non-empty lines after the
commit metadata. It is disabled if the "validate-metadata" option is
false.

Fixes: #6
Semver: minor

Author: evanlucas

lib/index.js

@@ -28,6 +28,7 @@ module.exports = class ValidateCommit extends EE {
     if (!this.opts['validate-metadata']) {
       this.disableRule('pr-url')
       this.disableRule('reviewers')
+      this.disableRule('metadata-end')
     }
   }
 

lib/rules/metadata-end.js

@@ -0,0 +1,47 @@
+'use strict'
+
+const id = 'metadata-end'
+
+module.exports = {
+  id: id
+, meta: {
+    description: 'enforce that metadata is at the end of commit messages'
+  , recommended: true
+  }
+, defaults: {}
+, options: {}
+, validate: (context, rule) => {
+    const parsed = context.toJSON()
+    const body = parsed.body
+    const end = parsed.metadata.end
+    if (end < body.length) {
+      const extra = body.slice(end + 1)
+      let lineNum = end + 1
+      for (var i = 0; i < extra.length; i++) {
+        if (extra[i]) {
+          lineNum += i
+          break
+        }
+      }
+
+      if (lineNum !== end + 1) {
+        context.report({
+          id: id
+        , message: 'commit metadata at end of message'
+        , string: body[lineNum]
+        , line: lineNum
+        , column: 0
+        , level: 'fail'
+        })
+        return
+      }
+    }
+
+    context.report({
+      id: id
+    , message: 'metadata is at end of message'
+    , string: ''
+    , level: 'pass'
+    })
+  }
+}

test/validator.js

@@ -76,6 +76,35 @@ Date:   Thu Mar 3 10:10:46 2016 -0600
     The properties on memoryUsage were not checked before,
     this commit checks them.`
 
+/* eslint-disable */
+const str6 = {
+  "sha": "c5545f2c63fe30b0cfcdafab18c26df8286881d0",
+  "url": "https://api.github.com/repos/nodejs/node/git/commits/c5545f2c63fe30b0cfcdafab18c26df8286881d0",
+  "html_url": "https://github.com/nodejs/node/commit/c5545f2c63fe30b0cfcdafab18c26df8286881d0",
+  "author": {
+    "name": "Anna Henningsen",
+    "email": "[email protected]",
+    "date": "2016-09-13T10:57:49Z"
+  },
+  "committer": {
+    "name": "Anna Henningsen",
+    "email": "[email protected]",
+    "date": "2016-09-19T12:50:57Z"
+  },
+  "tree": {
+    "sha": "b505c0ffa0555730e9f4cdb391d1ebeb48bb2f59",
+    "url": "https://api.github.com/repos/nodejs/node/git/trees/b505c0ffa0555730e9f4cdb391d1ebeb48bb2f59"
+  },
+  "message": "fs: fix handling of `uv_stat_t` fields\n\n`FChown` and `Chown` test that the `uid` and `gid` parameters\nthey receive are unsigned integers, but `Stat()` and `FStat()`\nwould return the corresponding fields of `uv_stat_t` as signed\nintegers. Applications which pass those these values directly\nto `Chown` may fail\n(e.g. for `nobody` on OS X, who has an `uid` of `-2`, see e.g.\nhttps://github.com/nodejs/node-v0.x-archive/issues/5890).\n\nThis patch changes the `Integer::New()` call for `uid` and `gid`\nto `Integer::NewFromUnsigned()`.\n\nAll other fields are kept as they are, for performance, but\nstrictly speaking the respective sizes of those\nfields aren’t specified, either.\n\nRef: https://github.com/npm/npm/issues/13918\nPR-URL: https://github.com/nodejs/node/pull/8515\nReviewed-By: Ben Noordhuis <[email protected]>\nReviewed-By: Sakthipriyan Vairamani <[email protected]>\nReviewed-By: James M Snell <[email protected]>\n\nundo accidental change to other fields of uv_fs_stat",
+  "parents": [
+    {
+      "sha": "4e76bffc0c7076a5901179e70c7b8a8f9fcd22e4",
+      "url": "https://api.github.com/repos/nodejs/node/git/commits/4e76bffc0c7076a5901179e70c7b8a8f9fcd22e4",
+      "html_url": "https://github.com/nodejs/node/commit/4e76bffc0c7076a5901179e70c7b8a8f9fcd22e4"
+    }
+  ]
+}
+/* eslint-enable */
 
 test('Validator - misc', (t) => {
   const v = new Validator()
@@ -213,5 +242,29 @@ test('Validator - real commits', (t) => {
     })
   })
 
+  t.test('non empty lines after metadata', (tt) => {
+    const v = new Validator()
+    v.lint(str6)
+    v.on('commit', (data) => {
+      const c = data.commit.toJSON()
+      tt.equal(c.sha, 'c5545f2c63fe30b0cfcdafab18c26df8286881d0', 'sha')
+      tt.equal(c.date, '2016-09-13T10:57:49Z', 'date')
+      tt.deepEqual(c.subsystems, ['fs'], 'subsystems')
+      tt.equal(c.prUrl, 'https://github.com/nodejs/node/pull/8515', 'pr')
+      tt.equal(c.revert, false, 'revert')
+      const msgs = data.messages
+      const filtered = msgs.filter((item) => {
+        return item.level === 'fail'
+      })
+      tt.equal(filtered.length, 1, 'messages.length')
+      const item = filtered[0]
+      tt.equal(item.id, 'metadata-end', 'id')
+      tt.equal(item.message, 'commit metadata at end of message', 'message')
+      tt.equal(item.line, 22, 'line')
+      tt.equal(item.column, 0, 'column')
+      tt.end()
+    })
+  })
+
   t.end()
 })