fix(commits): add helpful error when lastRelease not in history

Closes #61, Closes #50

src/lib/commits.js

@@ -1,9 +1,47 @@
 const { exec } = require('child_process')
 
-module.exports = function ({lastRelease}, cb) {
+const log = require('npmlog')
+
+const SemanticReleaseError = require('@semantic-release/error')
+
+module.exports = function ({lastRelease, branch}, cb) {
   const from = lastRelease.gitHead
   const range = (from ? from + '..' : '') + 'HEAD'
 
+  if (!from) return extract()
+
+  exec(`git branch --contains ${from}`, (err, stdout) => {
+    if (err) return cb(err)
+    let inHistory = false
+
+    const branches = stdout.split('\n')
+    .map((result) => {
+      if (branch === result.replace('*', '').trim()) {
+        inHistory = true
+        return null
+      }
+      return result.trim()
+    })
+    .filter(branch => !!branch)
+
+    if (!inHistory) {
+      log.error('commits',
+`The commit the last release of this package was derived from is no longer
+in the direct history of the "${branch}" branch.
+This means semantic-release can not extract the commits between now and then.
+This is usually caused by force pushing or releasing from an unrelated branch.
+You can recover from this error by publishing manually or restoring
+the commit "${from}".` + (branches.length ?
+        `\nHere is a list of branches that still contain the commit in question: \n * ${branches.join('\n * ')}` :
+        ''
+      ))
+      return cb(new SemanticReleaseError('Commit not in history', 'ENOTINHISTORY'))
+    }
+
+    extract()
+  })
+
+  function extract () {
     exec(
       `git log -E --format=%H==SPLIT==%B==END== ${range}`,
       (err, stdout) => {
@@ -23,3 +61,4 @@ module.exports = function ({lastRelease}, cb) {
       }
     )
   }
+}

test/mocks/child-process.js

@@ -5,6 +5,10 @@ const rawCommits = [
 
 module.exports = {
   exec: (command, cb) => {
+    if (/contains/.test(command)) {
+      return cb(null, `whatever\nmaster\n`)
+    }
+
     cb(
       null,
       /\.\.HEAD/.test(command) ?

test/specs/commits.js

@@ -7,7 +7,7 @@ const commits = proxyquire('../../dist/lib/commits', {
 
 test('commits since last release', (t) => {
   t.test('get all commits', (tt) => {
-    commits({lastRelease: {}}, (err, commits) => {
+    commits({lastRelease: {}, branch: 'master'}, (err, commits) => {
       tt.error(err)
       tt.is(commits.length, 2, 'all commits')
       tt.is(commits[0].hash, 'hash-one', 'parsed hash')
@@ -18,7 +18,7 @@ test('commits since last release', (t) => {
   })
 
   t.test('get commits since hash', (tt) => {
-    commits({lastRelease: {gitHead: 'hash'}}, (err, commits) => {
+    commits({lastRelease: {gitHead: 'hash'}, branch: 'master'}, (err, commits) => {
       tt.error(err)
       tt.is(commits.length, 1, 'specified commits')
       tt.is(commits[0].hash, 'hash-one', 'parsed hash')
@@ -28,5 +28,13 @@ test('commits since last release', (t) => {
     })
   })
 
+  t.test('get commits since hash', (tt) => {
+    commits({lastRelease: {gitHead: 'notinhistory'}, branch: 'notmaster'}, (err, commits) => {
+      tt.ok(err)
+      tt.is(err.code, 'ENOTINHISTORY')
+      tt.end()
+    })
+  })
+
   t.end()
 })

test/specs/pre.js

@@ -3,8 +3,10 @@ const proxyquire = require('proxyquire')
 
 require('../mocks/registry')
 const pre = proxyquire('../../dist/pre', {
+  './lib/commits': proxyquire('../../dist/lib/commits', {
     'child_process': require('../mocks/child-process')
   })
+})
 
 const versions = {
   available: '1.0.0'
@@ -21,7 +23,6 @@ const plugins = {
 const npm = {
   registry: 'http://registry.npmjs.org/',
   tag: 'latest'
-
 }
 
 test('full pre run', (t) => {
@@ -29,6 +30,7 @@ test('full pre run', (t) => {
     tt.plan(3)
 
     pre({
+      branch: 'master',
       npm,
       pkg: {name: 'available'},
       plugins
@@ -43,6 +45,7 @@ test('full pre run', (t) => {
     tt.plan(3)
 
     pre({
+      branch: 'master',
       npm,
       pkg: {name: 'unavailable'},
       plugins