feature #185 Improve the installation of -dev and -BETA versions (94noni, javiereguiluz)

This PR was merged into the 1.0-dev branch.

Discussion
----------

Improve the installation of -dev and -BETA versions

This finishes #159, which is related to #144 and #143.

The new behavior of the installer:

1) When installing a regular Symfony version, nothing changes from the previous installer.

2) When you install a `beta` version, you see a warning message:

![symfony-unstable-warning](https://cloud.githubusercontent.com/assets/73419/9811676/f14b6d02-5878-11e5-9220-301fcb671c8c.png)

3) When you try to install a `dev` version, you get a better error message and a link to the article that will solve your problem:

![symfony-dev-version](https://cloud.githubusercontent.com/assets/73419/9811642/c0bdc194-5878-11e5-9ee8-9af5e194f80b.png)

Commits
-------

6751701 Fixed again one test
3ea393a Fixed one test
f45a29a Fixed again the version parser regexp
165813c Added new tests for BETA and RC versions
9e41335 Updated the version parser regular expression
b26b217 Added support for RC versions and normalized version names
31765ca Made comparisons case insensitive because Composer doesn't differentiate 'BETA1' from 'beta1'
9b3cdc1 The trailing number is only available for BETA versions not for 'dev' versions
d03938f Fixed syntax issues
d67b4ad Improved the error message for "-dev" versions
4c26d2b Warn the user when downloading an unstable version
94a1f98 Simplified the new feature a bit
d58812a Installation dev/beta versions (143)

Author: javiereguiluz

src/Symfony/Installer/NewCommand.php

@@ -105,19 +105,14 @@ protected function execute(InputInterface $input, OutputInterface $output)
     protected function checkSymfonyVersionIsInstallable()
     {
         // 'latest' is a special version name that refers to the latest stable version
-        // available at the moment of installing Symfony
-        if ('latest' === $this->version) {
-            return $this;
-        }
-
         // 'lts' is a special version name that refers to the current long term support version
-        if ('lts' === $this->version) {
+        if (in_array($this->version, array('latest', 'lts'))) {
             return $this;
         }
 
         // validate semver syntax
-        if (!preg_match('/^2\.\d(?:\.\d{1,2})?$/', $this->version)) {
-            throw new \RuntimeException('The Symfony version should be 2.N or 2.N.M, where N = 0..9 and M = 0..99');
+        if (!preg_match('/^2\.\d(?:\.\d{1,2})?(?:-(?:dev|BETA\d*|RC\d*))?$/i', $this->version)) {
+            throw new \RuntimeException('The Symfony version must be 2.N or 2.N.M (where N and M are positive integers). The special "-dev", "-BETA" and "-RC" versions are also supported.');
         }
 
         if (preg_match('/^2\.\d$/', $this->version)) {
@@ -175,6 +170,25 @@ protected function checkSymfonyVersionIsInstallable()
             ));
         }
 
+        // "-dev" versions are not supported because Symfony doesn't provide packages for them
+        if (preg_match('/^.*\-dev$/i', $this->version)) {
+            throw new \RuntimeException(sprintf(
+                "The selected version (%s) cannot be installed because it hasn't\n".
+                "been published as a package yet. Read the following article for\n".
+                "an alternative installation method:\n\n".
+                "> How to Install or Upgrade to the Latest, Unreleased Symfony Version\n".
+                '> http://symfony.com/doc/current/cookbook/install/unstable_versions.html',
+                $this->version
+            ));
+        }
+
+        // warn the user when downloading an unstable version
+        if (preg_match('/^.*\-(BETA|RC)\d*$/i', $this->version)) {
+            $this->output->writeln("\n <bg=red> WARNING </> You are downloading an unstable Symfony version.");
+            // versions provided by the download server are case sensitive
+            $this->version = strtoupper($this->version);
+        }
+
         return $this;
     }
 

tests/Symfony/Installer/Tests/IntegrationTest.php

@@ -106,6 +106,12 @@ public function provideSymfonyInstallationData()
                 '/.*Symfony 2\.5\.6 was successfully installed.*/',
                 '/Symfony version 2\.5\.6 - app\/dev\/debug/',
             ),
+
+            array(
+                '2.7.0-BETA1',
+                '/.*Symfony 2\.7\.0\-BETA1 was successfully installed.*/',
+                '/Symfony version 2\.7\.0\-BETA1 - app\/dev\/debug/',
+            ),
         );
     }
 }