feature #32126 [Process] Allow writing portable "prepared" command lines (Simperfit)

This PR was merged into the 4.4 branch.

Discussion
----------

[Process] Allow writing portable "prepared" command lines

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | yes <!-- please update src/**/CHANGELOG.md files -->
| BC breaks?    | no     <!-- see https://symfony.com/bc -->
| Deprecations? | no <!-- please update UPGRADE-*.md and src/**/CHANGELOG.md files -->
| Tests pass?   | yes    <!-- please add some, will be required by reviewers -->
| Fixed tickets | #23778  <!-- #-prefixed issue number(s), if any -->
| License       | MIT
| Doc PR        | https://github.com/symfony/symfony-docs/pull/11802 <!-- required for new features -->

Hey here, it's me, again !

I've talked with @nicolas-grekas and he gave me a new way of writing this feature that will not be a problem for people using things like {{ toto }} since we are using the linux style of using envvar, the replaced arguments is only replaced when using windows.

This should not break anything and work as expected!

see https://github.com/symfony/symfony/pull/24763

This makes `"$FOO"` work seamlessly on Linux and on Windows to reference an env var (that can be provided when calling e.g. the "run" method)

Commits
-------

3f8354f58f [Process] Allow writing portable "prepared" command lines

src/Symfony/Component/Process/Process.php

@@ -291,6 +291,12 @@ class Process implements \IteratorAggregate
         $this->hasCallback = null !== $callback;
         $descriptors = $this->getDescriptors();
 
+        if ($this->env) {
+            $env += $this->env;
+        }
+
+        $env += $this->getDefaultEnv();
+
         if (\is_array($commandline = $this->commandline)) {
             $commandline = implode(' ', array_map([$this, 'escapeArgument'], $commandline));
 
@@ -298,13 +304,10 @@ class Process implements \IteratorAggregate
                 // exec is mandatory to deal with sending a signal to the process
                 $commandline = 'exec '.$commandline;
             }
+        } else {
+            $commandline = $this->replacePlaceholders($commandline, $env);
         }
 
-        if ($this->env) {
-            $env += $this->env;
-        }
-        $env += $this->getDefaultEnv();
-
         $options = ['suppress_errors' => true];
 
         if ('\\' === \DIRECTORY_SEPARATOR) {
@@ -1632,6 +1635,17 @@ class Process implements \IteratorAggregate
         return '"'.str_replace(['"', '^', '%', '!', "\n"], ['""', '"^^"', '"^%"', '"^!"', '!LF!'], $argument).'"';
     }
 
+    private function replacePlaceholders(string $commandline, array $env)
+    {
+        return preg_replace_callback('/"\$([_a-zA-Z]++[_a-zA-Z0-9]*+)"/', function ($matches) use ($commandline, $env) {
+            if (!isset($env[$matches[1]]) || false === $env[$matches[1]]) {
+                throw new InvalidArgumentException(sprintf('Command line is missing a value for key %s: %s.', $matches[0], $commandline));
+            }
+
+            return '\\' === \DIRECTORY_SEPARATOR ? $this->escapeArgument($env[$matches[1]]) : $matches[0];
+        }, $commandline);
+    }
+
     private function getDefaultEnv()
     {
         $env = [];

src/Symfony/Component/Process/Tests/ProcessTest.php

@@ -1500,6 +1500,50 @@ EOTXT;
         yield [1.1];
     }
 
+    public function testPreparedCommand()
+    {
+        $p = Process::fromShellCommandline('echo "$abc"DEF');
+        $p->run(null, ['abc' => 'ABC']);
+
+        $this->assertSame('ABCDEF', rtrim($p->getOutput()));
+    }
+
+    public function testPreparedCommandMulti()
+    {
+        $p = Process::fromShellCommandline('echo "$abc""$def"');
+        $p->run(null, ['abc' => 'ABC', 'def' => 'DEF']);
+
+        $this->assertSame('ABCDEF', rtrim($p->getOutput()));
+    }
+
+    public function testPreparedCommandWithQuoteInIt()
+    {
+        $p = Process::fromShellCommandline('php -r "$code" "$def"');
+        $p->run(null, ['code' => 'echo $argv[1];', 'def' => '"DEF"']);
+
+        $this->assertSame('"DEF"', rtrim($p->getOutput()));
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Process\Exception\InvalidArgumentException
+     * @expectedExceptionMessage Command line is missing a value for key "$abc": echo "$abc".
+     */
+    public function testPreparedCommandWithMissingValue()
+    {
+        $p = Process::fromShellCommandline('echo "$abc"');
+        $p->run(null, ['bcd' => 'BCD']);
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Process\Exception\InvalidArgumentException
+     * @expectedExceptionMessage Command line is missing a value for key "$abc": echo "$abc".
+     */
+    public function testPreparedCommandWithNoValues()
+    {
+        $p = Process::fromShellCommandline('echo "$abc"');
+        $p->run(null, []);
+    }
+
     public function testEnvArgument()
     {
         $env = ['FOO' => 'Foo', 'BAR' => 'Bar'];