Exit on error when something was wrong executing the command

When something abnormal happens (wrong configuration, missing stuff,
connectivity problems, etc., the phpcs execution can end with error.

But, if max-warnings is enabled (>=0), then the count of errors and
warnings (that is always 0 on error) gets precedence, hiding the
real exit status. Hence it passes, when really it was not executed.

Now we detect those abnormal situations and exit with error when
something in the execution goes wrong.

Covered with tests, checking all the possible max-warnings combinations.

docs/CHANGELOG.md

@@ -15,6 +15,7 @@ The format of this change log follows the advice given at [Keep a CHANGELOG](htt
 
 ### Fixed
 - Solved a problem with the validation of `dataformat` plugin lang strings.
+- Fixed a problem with the `phpcs` command returning with success when some (configuration, installation, ...) problem was causing it not to be executed at all.
 
 ## [4.4.5] - 2024-04-03
 ### Changed

src/Command/CodeCheckerCommand.php

@@ -178,6 +178,13 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 
         // Arrived here, we are playing with max-warnings, so we have to decide the exit code
         // based on the existence of errors and the number of warnings compared with the threshold.
+
+        // Verify that the summary file was created. If not, something went wrong with the execution.
+        if (!file_exists($this->tempFile)) {
+            return 1;
+        }
+
+        // Let's inspect the summary file to get the total number of errors and warnings.
         $totalErrors   = 0;
         $totalWarnings = 0;
         $jsonFile      = trim(file_get_contents($this->tempFile));

tests/Command/CodeCheckerCommandTest.php

@@ -324,4 +324,43 @@ public function testExecuteNoPlugin()
         $this->expectException(\InvalidArgumentException::class);
         $this->executeCommand('/path/to/no/plugin');
     }
+
+    /**
+     * Data provider for testCommandFailedSomethingIsWrong.
+     *
+     * @return array of options to use for the command, all them known to fail
+     */
+    public function commandFailedSomethingIsWrongProvider()
+    {
+        return [
+            'default' => [
+                ['--standard' => 'chocolate', '--max-warnings' => -1],
+                'ERROR: the "chocolate" coding standard is not installed',
+            ],
+            'zero' => [
+                ['--standard' => 'chocolate', '--max-warnings' => 0],
+                'ERROR: the "chocolate" coding standard is not installed',
+            ],
+            'positive' => [
+                ['--standard' => 'chocolate', '--max-warnings' => 1],
+                'ERROR: the "chocolate" coding standard is not installed',
+            ],
+        ];
+    }
+
+    /**
+     * Verify that if anything goes wrong, the command fails, no matter the max-warnings.
+     *
+     * @param array  $options configuration to use for the command
+     * @param string $output  Expected output (substring matching is enough)
+     *
+     * @dataProvider commandFailedSomethingIsWrongProvider
+     */
+    public function testCommandFailedSomethingIsWrong(array $options, string $output)
+    {
+        // Verify that with incorrect configurations we are getting the command always failed.
+        $commandTester = $this->executeCommand($this->pluginDir, $options);
+        $this->assertSame(1, $commandTester->getStatusCode());
+        $this->assertStringContainsString($output, $commandTester->getDisplay());
+    }
 }