feat: add support for fallbackTags

Author: boennemann

src/index.js

@@ -3,7 +3,7 @@ const SemanticReleaseError = require('@semantic-release/error')
 const npmlog = require('npmlog')
 const RegClient = require('npm-registry-client')
 
-module.exports = function (pluginConfig, {pkg, npm, plugins}, cb) {
+module.exports = function (pluginConfig, {pkg, npm, plugins, options}, cb) {
   npmlog.level = npm.loglevel || 'warn'
   let clientConfig = {log: npmlog}
   // disable retries for tests
@@ -22,9 +22,21 @@ module.exports = function (pluginConfig, {pkg, npm, plugins}, cb) {
 
     if (err) return cb(err)
 
-    const version = data['dist-tags'][npm.tag]
+    let version = data['dist-tags'][npm.tag]
 
-    if (!version) return cb(new SemanticReleaseError(`There is no release with the dist-tag "${npm.tag}" yet. Tag a version first.`, 'ENODISTTAG'))
+    if (!version &&
+      options &&
+      options.fallbackTags &&
+      options.fallbackTags[npm.tag] &&
+      data['dist-tags'][options.fallbackTags[npm.tag]]) {
+      version = data['dist-tags'][options.fallbackTags[npm.tag]]
+    }
+
+    if (!version) {
+      return cb(new SemanticReleaseError(
+`There is no release with the dist-tag "${npm.tag}" yet.
+Tag a version manually or define "fallbackTags".`, 'ENODISTTAG'))
+    }
 
     cb(null, {
       version,

test/mocks/registry.js

@@ -19,6 +19,7 @@ module.exports = nock('http://registry.npmjs.org')
   .get('/available')
   .reply(200, availableModule)
   .get('/tagged')
+  .times(2)
   .reply(200, availableModule)
   .get('/untagged')
   .reply(200, availableModule)

test/specs/index.js

@@ -11,7 +11,7 @@ const npm = {
 }
 
 test('last release from registry', (t) => {
-  t.plan(5)
+  t.plan(6)
 
   t.test('get release from package name', (tt) => {
     lastRelease({}, {
@@ -41,6 +41,25 @@ test('last release from registry', (t) => {
     })
   })
 
+  t.test('get release from a fallbackTag', (tt) => {
+    lastRelease({}, {
+      pkg: {name: 'tagged'},
+      options: {
+        fallbackTags: {
+          bar: 'latest'
+        }
+      },
+      npm: defaults({tag: 'bar'}, npm)
+    }, (err, release) => {
+      tt.error(err)
+      tt.is(release.version, '1.33.7', 'version')
+      tt.is(release.gitHead, 'HEAD', 'gitHead')
+      tt.is(release.tag, 'bar', 'dist-tag')
+
+      tt.end()
+    })
+  })
+
   t.test('get error from an untagged package\'s name', (tt) => {
     lastRelease({}, {
       pkg: {name: 'untagged'},