fix(parse): work with unknown "from" versions

dependabot sometimes sends PRs without a "from" version number, this breaks the range detection
logic, the work around is to not fail if no "from" version is declared, and to fallback to manual
merging when version range comparision is required

Fixes #31

action/lib/parse.js

@@ -45,13 +45,13 @@ export default function ({ title, labels = [], config = [], dependencies = {} })
   const from = title.match(new RegExp('from v?' + regex.semver.source))?.groups
   const to = title.match(new RegExp('to v?' + regex.semver.source))?.groups
 
-  if (!from || !to) {
+  if (!to) {
     core.warning('failed to parse title: no recognizable versions')
     return process.exit(0) // soft exit
   }
 
   // exit early
-  if (!semver.valid(from.version) || !semver.valid(to.version)) {
+  if (!semver.valid(to.version)) {
     core.warning('failed to parse title: invalid semver')
     return process.exit(0) // soft exit
   }
@@ -78,13 +78,17 @@ export default function ({ title, labels = [], config = [], dependencies = {} })
   }
 
   // log
-  core.info(`from: ${from.version}`)
+  core.info(`from: ${from ? from.version : 'unknown'}`)
   core.info(`to: ${to.version}`)
   core.info(`dependency type: ${isProd ? 'production' : 'development'}`)
   core.info(`security critical: ${isSecurity}`)
 
   // analyze with semver
-  const versionChange = semver.diff(from.version, to.version)
+  let versionChange
+
+  if (from && from.version) {
+    versionChange = semver.diff(from.version, to.version)
+  }
 
   // check all configuration variants to see if one matches
   for (const { match: { dependency_name, dependency_type, update_type } } of config) {
@@ -119,6 +123,17 @@ export default function ({ title, labels = [], config = [], dependencies = {} })
           // skip when config is for security update and PR is not security
           if (type === 'security' && !isSecurity) continue
 
+          if (target === 'all') {
+            core.info(`${dependency_name || dependency_type}:${update_type} detected, will auto-merge`)
+            return true
+          }
+
+          // when there is no "from" version, there is no change detected
+          if (!versionChange) {
+            core.warning('no version range detected in PR title')
+            continue
+          }
+
           // evaluate weight of detected change
           if ((weight[target] || 0) >= (weight[versionChange] || 0)) {
           // tell dependabot to merge

action/test/parse/dep-name.js

@@ -85,7 +85,8 @@ tap.test('parse -> out of range', async assert => {
 tap.test('parse -> edge cases', async assert => {
   const titles = [
     { message: 'Update rake requirement from 10.4.0 to 13.0.0', name: 'rake' },
-    { message: 'Bump actions/cache from v2.0.0 to v2.1.2', name: 'actions/cache' }
+    { message: 'Bump actions/cache from v2.0.0 to v2.1.2', name: 'actions/cache' },
+    { message: 'Update actions/setup-python requirement to v2.1.4', name: 'actions/setup-python' }
   ]
 
   assert.plan(titles.length * 3)

action/test/parse/match-target.js

@@ -8,8 +8,8 @@ import fs from 'fs'
 // module
 import parse from '../../lib/parse.js'
 
-function config (target) {
-  return [{ match: { dependency_type: 'all', update_type: `semver:${target}` } }]
+function config (update_type) {
+  return [{ match: { dependency_type: 'all', update_type } }]
 }
 
 tap.test('title -> in range', async assert => {
@@ -20,7 +20,7 @@ tap.test('title -> in range', async assert => {
 
   const options = {
     title: 'chore(deps): bump api-problem from 6.1.2 to 6.1.4 in /path',
-    config: config('major')
+    config: config('semver:major')
   }
 
   assert.ok(parse(options))
@@ -36,6 +36,60 @@ tap.test('title -> in range', async assert => {
   fs.existsSync.restore()
 })
 
+tap.test('title -> in range, no from', async assert => {
+  assert.plan(8)
+
+  sinon.stub(core, 'info')
+  // sinon.stub(core, 'warning')
+  sinon.stub(fs, 'existsSync').returns(false)
+
+  const options = {
+    title: 'Update actions/setup-python requirement to v2.1.4 in /path',
+    config: config('all')
+  }
+
+  assert.ok(parse(options))
+  assert.ok(core.info.called)
+  // assert.ok(core.warning.called)
+  assert.equal(core.info.getCall(0)?.firstArg, 'title: "Update actions/setup-python requirement to v2.1.4 in /path"')
+  assert.equal(core.info.getCall(1)?.firstArg, 'depName: actions/setup-python')
+  assert.equal(core.info.getCall(2)?.firstArg, 'from: unknown')
+  assert.equal(core.info.getCall(3)?.firstArg, 'to: 2.1.4')
+  assert.equal(core.info.getCall(6)?.firstArg, 'config: all:all')
+  assert.equal(core.info.getCall(7)?.firstArg, 'all:all detected, will auto-merge')
+  // assert.equal(core.warning.getCall(0)?.firstArg, 'no version range detected in PR title')
+
+  core.info.restore()
+  fs.existsSync.restore()
+})
+
+tap.test('title -> in range, no from', async assert => {
+  assert.plan(8)
+
+  sinon.stub(core, 'info')
+  // sinon.stub(core, 'warning')
+  sinon.stub(fs, 'existsSync').returns(false)
+
+  const options = {
+    title: 'Update actions/setup-python requirement to v2.1.4 in /path',
+    config: config('semver:all')
+  }
+
+  assert.ok(parse(options))
+  assert.ok(core.info.called)
+  // assert.ok(core.warning.called)
+  assert.equal(core.info.getCall(0)?.firstArg, 'title: "Update actions/setup-python requirement to v2.1.4 in /path"')
+  assert.equal(core.info.getCall(1)?.firstArg, 'depName: actions/setup-python')
+  assert.equal(core.info.getCall(2)?.firstArg, 'from: unknown')
+  assert.equal(core.info.getCall(3)?.firstArg, 'to: 2.1.4')
+  assert.equal(core.info.getCall(6)?.firstArg, 'config: all:semver:all')
+  assert.equal(core.info.getCall(7)?.firstArg, 'all:semver:all detected, will auto-merge')
+  // assert.equal(core.warning.getCall(0)?.firstArg, 'no version range detected in PR title')
+
+  core.info.restore()
+  fs.existsSync.restore()
+})
+
 tap.test('parse -> out of range', async assert => {
   assert.plan(5)
 
@@ -44,7 +98,7 @@ tap.test('parse -> out of range', async assert => {
 
   const options = {
     title: 'chore(deps): bump api-problem from 6.1.2 to 7.0.0 in /path',
-    config: config('patch')
+    config: config('semver:patch')
   }
 
   assert.notOk(parse(options), false)
@@ -56,3 +110,31 @@ tap.test('parse -> out of range', async assert => {
   core.info.restore()
   fs.existsSync.restore()
 })
+
+tap.test('title -> out of range, no from', async assert => {
+  assert.plan(10)
+
+  sinon.stub(core, 'info')
+  sinon.stub(core, 'warning')
+  sinon.stub(fs, 'existsSync').returns(false)
+
+  const options = {
+    title: 'Update actions/setup-python requirement to v2.1.4 in /path',
+    config: config('semver:major')
+  }
+
+  assert.notOk(parse(options))
+  assert.ok(core.info.called)
+  assert.ok(core.warning.called)
+  assert.equal(core.info.getCall(0)?.firstArg, 'title: "Update actions/setup-python requirement to v2.1.4 in /path"')
+  assert.equal(core.info.getCall(1)?.firstArg, 'depName: actions/setup-python')
+  assert.equal(core.info.getCall(2)?.firstArg, 'from: unknown')
+  assert.equal(core.info.getCall(3)?.firstArg, 'to: 2.1.4')
+  assert.equal(core.info.getCall(6)?.firstArg, 'config: all:semver:major')
+  assert.equal(core.info.getCall(7)?.firstArg, 'manual merging required')
+  assert.equal(core.warning.getCall(0)?.firstArg, 'no version range detected in PR title')
+
+  core.info.restore()
+  core.warning.restore()
+  fs.existsSync.restore()
+})