Allow installing old versions not listed in the package info

Fixes atom#733

Rather than relying only on the JSON returned for the package, we now fall back
to the `GET /api/packages/:package_name/versions/:version_name` endpoint if
necessary, and use the tarball URL from there if we find one.

Since I changed the code to use `version` to mean a version JSON object, I
renamed `packageVersion` to `versionName` in a few places to be more clear. I
also rely on `version.version` containing the version name, which required
updating some test fixtures.

This also adds tests for installing old versions in general and producing the
expected error message if a version isn't found.

spec/fixtures/atom-2048.json

@@ -8,7 +8,8 @@
     "1.2.3": {
       "dist": {
         "tarball": "http://localhost:3000/tarball/test-module-1.0.0.tgz"
-      }
+      },
+      "version": "1.2.3"
     }
   }
 }

spec/fixtures/install-multi-version.json

@@ -15,7 +15,8 @@
       },
       "dist": {
         "tarball": "http://localhost:3000/tarball/test-module-1.0.0.tgz"
-      }
+      },
+      "version": "0.3.0"
     },
     "0.2.0": {
       "engines": {

spec/fixtures/install-test-module-version-0.2.0.json

@@ -0,0 +1,6 @@
+{
+    "dist": {
+        "tarball": "http://localhost:3000/tarball/test-module-0.2.0.tgz"
+    },
+    "version": "0.2.0"
+}

spec/fixtures/install-test-module-with-bin.json

@@ -7,7 +7,8 @@
         "2.0.0": {
             "dist": {
                 "tarball": "http://localhost:3000/tarball/test-module-with-bin-2.0.0.tgz"
-            }
+            },
+            "version": "2.0.0"
         }
     }
 }

spec/fixtures/install-test-module-with-symlink.json

@@ -7,7 +7,8 @@
         "5.0.0": {
             "dist": {
                 "tarball": "http://localhost:3000/tarball/test-module-with-symlink-5.0.0.tgz"
-            }
+            },
+            "version": "5.0.0"
         }
     }
 }

spec/fixtures/install-test-module.json

@@ -6,8 +6,15 @@
     "versions": {
         "0.4.0": {
             "dist": {
-                "tarball": "http://localhost:3000/tarball/test-module-1.0.0.tgz"
-            }
+                "tarball": "http://localhost:3000/tarball/test-module-0.4.0.tgz"
+            },
+            "version": "0.4.0"
+        },
+        "0.3.0": {
+            "dist": {
+                "tarball": "http://localhost:3000/tarball/test-module-0.3.0.tgz"
+            },
+            "version": "0.3.0"
         }
     }
 }

spec/fixtures/install-test-module2.json

@@ -7,7 +7,8 @@
         "2.0.0": {
             "dist": {
                 "tarball": "http://localhost:3000/tarball/test-module2-2.0.0.tgz"
-            }
+            },
+            "version": "2.0.0"
         }
     }
 }

spec/fixtures/native-package.json

@@ -7,7 +7,8 @@
         "1.0.0": {
             "dist": {
                 "tarball": "http://localhost:3000/tarball/native-package-1.0.0.tgz"
-            }
+            },
+            "version": "1.0.0"
         }
     }
 }

spec/install-spec.coffee

@@ -37,12 +37,20 @@ describe 'apm install', ->
         response.sendfile path.join(__dirname, 'fixtures', 'node_x64.lib')
       app.get '/node/v0.10.3/SHASUMS256.txt', (request, response) ->
         response.sendfile path.join(__dirname, 'fixtures', 'SHASUMS256.txt')
+      app.get '/tarball/test-module-0.2.0.tgz', (request, response) ->
+        response.sendfile path.join(__dirname, 'fixtures', 'test-module-0.2.0.tgz')
+      app.get '/tarball/test-module-0.3.0.tgz', (request, response) ->
+        response.sendfile path.join(__dirname, 'fixtures', 'test-module-0.3.0.tgz')
+      app.get '/tarball/test-module-0.4.0.tgz', (request, response) ->
+        response.sendfile path.join(__dirname, 'fixtures', 'test-module-0.4.0.tgz')
       app.get '/tarball/test-module-1.0.0.tgz', (request, response) ->
         response.sendfile path.join(__dirname, 'fixtures', 'test-module-1.0.0.tgz')
       app.get '/tarball/test-module2-2.0.0.tgz', (request, response) ->
         response.sendfile path.join(__dirname, 'fixtures', 'test-module2-2.0.0.tgz')
       app.get '/packages/test-module', (request, response) ->
         response.sendfile path.join(__dirname, 'fixtures', 'install-test-module.json')
+      app.get '/packages/test-module/versions/0.2.0', (request, response) ->
+        response.sendfile path.join(__dirname, 'fixtures', 'install-test-module-version-0.2.0.json')
       app.get '/packages/test-module2', (request, response) ->
         response.sendfile path.join(__dirname, 'fixtures', 'install-test-module2.json')
       app.get '/packages/test-rename', (request, response) ->
@@ -201,6 +209,43 @@ describe 'apm install', ->
               expect(fs.existsSync(path.join(testModuleDirectory, 'package.json'))).toBeTruthy()
               expect(callback.mostRecentCall.args[0]).toBeNull()
 
+    describe 'when an explicit version is specified', ->
+      it 'installs the version', ->
+        testModuleDirectory = path.join(atomHome, 'packages', 'test-module')
+
+        callback = jasmine.createSpy('callback')
+        apm.run(['install', "[email protected]"], callback)
+
+        waitsFor 'waiting for install to complete', 600000, ->
+          callback.callCount is 1
+
+        runs ->
+          expect(callback.mostRecentCall.args[0]).toBeNull()
+          expect(JSON.parse(fs.readFileSync(path.join(testModuleDirectory, 'package.json'))).version).toBe "0.3.0"
+
+      it 'allows installing versions not in the package JSON', ->
+        testModuleDirectory = path.join(atomHome, 'packages', 'test-module')
+
+        callback = jasmine.createSpy('callback')
+        apm.run(['install', "[email protected]"], callback)
+
+        waitsFor 'waiting for install to complete', 600000, ->
+          callback.callCount is 1
+
+        runs ->
+          expect(callback.mostRecentCall.args[0]).toBeNull()
+          expect(JSON.parse(fs.readFileSync(path.join(testModuleDirectory, 'package.json'))).version).toBe "0.2.0"
+
+      it 'gives an error when installing a nonexistent version', ->
+        callback = jasmine.createSpy('callback')
+        apm.run(['install', "[email protected]"], callback)
+
+        waitsFor 'waiting for install to complete', 600000, ->
+          callback.callCount is 1
+
+        runs ->
+          expect(callback.mostRecentCall.args[0]).toBe 'Package version: 0.1.0 not found'
+
     describe 'when multiple package names are specified', ->
       it 'installs all packages', ->
         testModuleDirectory = path.join(atomHome, 'packages', 'test-module')

spec/stars-spec.coffee

@@ -25,8 +25,8 @@ describe 'apm stars', ->
       response.sendfile path.join(__dirname, 'fixtures', 'node_x64.lib')
     app.get '/node/v0.10.3/SHASUMS256.txt', (request, response) ->
       response.sendfile path.join(__dirname, 'fixtures', 'SHASUMS256.txt')
-    app.get '/tarball/test-module-1.0.0.tgz', (request, response) ->
-      response.sendfile path.join(__dirname, 'fixtures', 'test-module-1.0.0.tgz')
+    app.get '/tarball/test-module-0.4.0.tgz', (request, response) ->
+      response.sendfile path.join(__dirname, 'fixtures', 'test-module-0.4.0.tgz')
     app.get '/tarball/test-module2-2.0.0.tgz', (request, response) ->
       response.sendfile path.join(__dirname, 'fixtures', 'test-module2-2.0.0.tgz')
     app.get '/packages/test-module', (request, response) ->

src/install.coffee

@@ -235,6 +235,30 @@ class Install extends Command
         else
           callback("No releases available for #{packageName}")
 
+  # Request package version information from the atom.io API.
+  #
+  # packageName - The string name of the package to request.
+  # versionName - The string version of the package to request.
+  # callback - The function to invoke when the request completes with an error
+  #            as the first argument and an object as the second.
+  requestPackageVersion: (packageName, versionName, callback) ->
+    requestSettings =
+      url: "#{config.getAtomPackagesUrl()}/#{packageName}/versions/#{versionName}"
+      json: true
+      retries: 4
+    request.get requestSettings, (error, response, body={}) ->
+      if error?
+        message = "Request for package version information failed: #{error.message}"
+        message += " (#{error.code})" if error.code
+        callback(message)
+      else if response.statusCode is 404
+        callback("Package version: #{versionName} not found")
+      else if response.statusCode isnt 200
+        message = request.getErrorMessage(response, body)
+        callback("Request for package version information failed: #{message}")
+      else
+        callback(null, body)
+
   # Download a package tarball.
   #
   # packageUrl - The string tarball URL to request
@@ -271,13 +295,13 @@ class Install extends Command
   # Get the path to the package from the local cache.
   #
   #  packageName - The string name of the package.
-  #  packageVersion - The string version of the package.
+  #  versionName - The string version of the package.
   #  callback - The function to call with error and cachePath arguments.
   #
   # Returns a path to the cached tarball or undefined when not in the cache.
-  getPackageCachePath: (packageName, packageVersion, callback) ->
+  getPackageCachePath: (packageName, versionName, callback) ->
     cacheDir = config.getCacheDirectory()
-    cachePath = path.join(cacheDir, packageName, packageVersion, 'package.tgz')
+    cachePath = path.join(cacheDir, packageName, versionName, 'package.tgz')
     if fs.isFileSync(cachePath)
       tempPath = path.join(temp.mkdirSync(), path.basename(cachePath))
       fs.cp cachePath, tempPath, (error) ->
@@ -287,16 +311,16 @@ class Install extends Command
           callback(null, tempPath)
     else
       process.nextTick ->
-        callback(new Error("#{packageName}@#{packageVersion} is not in the cache"))
+        callback(new Error("#{packageName}@#{versionName} is not in the cache"))
 
   # Is the package at the specified version already installed?
   #
   #  * packageName: The string name of the package.
-  #  * packageVersion: The string version of the package.
-  isPackageInstalled: (packageName, packageVersion) ->
+  #  * versionName: The string version of the package.
+  isPackageInstalled: (packageName, versionName) ->
     try
       {version} = CSON.readFileSync(CSON.resolve(path.join('node_modules', packageName, 'package'))) ? {}
-      packageVersion is version
+      versionName is version
     catch error
       false
 
@@ -310,16 +334,16 @@ class Install extends Command
   #            error as the first argument.
   installRegisteredPackage: (metadata, options, callback) ->
     packageName = metadata.name
-    packageVersion = metadata.version
+    versionName = metadata.version
 
     installGlobally = options.installGlobally ? true
     unless installGlobally
-      if packageVersion and @isPackageInstalled(packageName, packageVersion)
+      if versionName and @isPackageInstalled(packageName, versionName)
         callback(null, {})
         return
 
     label = packageName
-    label += "@#{packageVersion}" if packageVersion
+    label += "@#{versionName}" if versionName
     unless options.argv.json
       process.stdout.write "Installing #{label} "
       if installGlobally
@@ -330,50 +354,69 @@ class Install extends Command
         @logFailure()
         callback(error)
       else
-        packageVersion ?= @getLatestCompatibleVersion(pack)
-        unless packageVersion
+        versionName ?= @getLatestCompatibleVersion(pack)
+        unless versionName
           @logFailure()
           callback("No available version compatible with the installed Atom version: #{@installedAtomVersion}")
           return
 
-        {tarball} = pack.versions[packageVersion]?.dist ? {}
-        unless tarball
-          @logFailure()
-          callback("Package version: #{packageVersion} not found")
-          return
-
-        commands = []
-        commands.push (next) =>
-          @getPackageCachePath packageName, packageVersion, (error, packagePath) =>
-            if packagePath
-              next(null, packagePath)
-            else
-              @downloadPackage(tarball, installGlobally, next)
-        installNode = options.installNode ? true
-        if installNode
-          commands.push (packagePath, next) =>
-            @installNode (error) -> next(error, packagePath)
-        commands.push (packagePath, next) =>
-          @installModule(options, pack, packagePath, next)
-        if installGlobally and (packageName.localeCompare(pack.name, 'en', {sensitivity: 'accent'}) isnt 0)
-          commands.push (newPack, next) => # package was renamed; delete old package folder
-            fs.removeSync(path.join(@atomPackagesDirectory, packageName))
-            next(null, newPack)
-        commands.push ({installPath}, next) ->
-          if installPath?
-            metadata = JSON.parse(fs.readFileSync(path.join(installPath, 'package.json'), 'utf8'))
-            json = {installPath, metadata}
-            next(null, json)
-          else
-            next(null, {}) # installed locally, no install path data
-
-        async.waterfall commands, (error, json) =>
-          unless installGlobally
+        version = pack.versions[versionName]
+        unless version
+          # The package information only has recent versions, so do another API
+          # request in case this is an older version.
+          @requestPackageVersion packageName, versionName, (error, version) =>
             if error?
               @logFailure()
+              callback(error)
             else
-              @logSuccess() unless options.argv.json
-          callback(error, json)
+              @installPackageVersion(packageName, pack, version, options, callback)
+          return
+        @installPackageVersion(packageName, pack, version, options, callback)
+
+  # Install the package with the given name and optional version
+  #
+  # packageName - The originally-requested package name. This might differ from
+  #               pack.name if the package was renamed.
+  # pack - The package object returned by the API.
+  # version - The version object returned by the API.
+  # options - The installation options object.
+  # callback - The function to invoke when installation completes with an
+  #            error as the first argument.
+  installPackageVersion: (packageName, pack, version, options, callback) ->
+    installGlobally = options.installGlobally ? true
+    tarball = version.dist.tarball
+    commands = []
+    commands.push (next) =>
+      @getPackageCachePath packageName, version.version, (error, packagePath) =>
+        if packagePath
+          next(null, packagePath)
+        else
+          @downloadPackage(tarball, installGlobally, next)
+    installNode = options.installNode ? true
+    if installNode
+      commands.push (packagePath, next) =>
+        @installNode (error) -> next(error, packagePath)
+    commands.push (packagePath, next) =>
+      @installModule(options, pack, packagePath, next)
+    if installGlobally and (packageName.localeCompare(pack.name, 'en', {sensitivity: 'accent'}) isnt 0)
+      commands.push (newPack, next) => # package was renamed; delete old package folder
+        fs.removeSync(path.join(@atomPackagesDirectory, packageName))
+        next(null, newPack)
+    commands.push ({installPath}, next) ->
+      if installPath?
+        metadata = JSON.parse(fs.readFileSync(path.join(installPath, 'package.json'), 'utf8'))
+        json = {installPath, metadata}
+        next(null, json)
+      else
+        next(null, {}) # installed locally, no install path data
+
+    async.waterfall commands, (error, json) =>
+      unless installGlobally
+        if error?
+          @logFailure()
+        else
+          @logSuccess() unless options.argv.json
+      callback(error, json)
 
   # Install all the package dependencies found in the package.json file.
   #