Cli: suggest close option when typo is made

Author: janedbal

src/Cli.php

@@ -3,11 +3,15 @@
 namespace ShipMonk\ComposerDependencyAnalyser;
 
 use ShipMonk\ComposerDependencyAnalyser\Exception\InvalidCliException;
+use function array_keys;
 use function array_slice;
 use function is_dir;
 use function is_file;
+use function levenshtein;
+use function strlen;
 use function strpos;
 use function substr;
+use function trim;
 
 class Cli
 {
@@ -54,23 +58,26 @@ public function __construct(string $cwd, array $argv)
             $startsWithDashDash = strpos($arg, '--') === 0;
 
             if ($startsWithDash && !$startsWithDashDash) {
-                throw new InvalidCliException("Unknown option $arg, see --help");
+                $suggestedOption = $this->suggestOption($arg);
+                throw new InvalidCliException("Unknown option $arg, $suggestedOption");
             }
 
             if (!$startsWithDashDash) {
                 if (is_file($cwd . '/' . $arg) || is_dir($cwd . '/' . $arg)) {
                     throw new InvalidCliException("Cannot pass paths ($arg) to analyse as arguments, use --config instead.");
                 }
 
-                throw new InvalidCliException("Unknown argument $arg, see --help");
+                $suggestedOption = $this->suggestOption($arg);
+                throw new InvalidCliException("Unknown argument $arg, $suggestedOption");
             }
 
             /** @var string $noDashesArg this is never false as we know it starts with -- */
             $noDashesArg = substr($arg, 2);
             $optionName = $this->getKnownOptionName($noDashesArg);
 
             if ($optionName === null) {
-                throw new InvalidCliException("Unknown option $arg, see --help");
+                $suggestedOption = $this->suggestOption($noDashesArg);
+                throw new InvalidCliException("Unknown option $arg, $suggestedOption");
             }
 
             if ($this->isOptionWithRequiredValue($optionName)) {
@@ -186,4 +193,29 @@ public function getProvidedOptions(): CliOptions
         return $options;
     }
 
+    /**
+     * Params inspired by tracy/tracy
+     */
+    private function suggestOption(string $input): string
+    {
+        $value = trim($input, '-');
+        $options = array_keys(self::OPTIONS);
+
+        $bestGuess = null;
+        $minDistance = (strlen($value) / 4 + 1) * 10 + .1;
+
+        foreach ($options as $option) {
+            $distance = levenshtein($option, $value, 9, 11, 9);
+
+            if ($distance > 0 && $distance < $minDistance) {
+                $minDistance = $distance;
+                $bestGuess = $option;
+            }
+        }
+
+        return $bestGuess === null
+            ? 'see --help'
+            : "did you mean --$bestGuess?";
+    }
+
 }

tests/CliTest.php

@@ -114,6 +114,51 @@ public function validationDataProvider(): iterable
             'Missing argument value in --composer-json=, see --help',
             ['bin/script.php', '--composer-json='],
         ];
+
+        yield 'suggestion #1' => [
+            'Unknown option --hep, did you mean --help?',
+            ['bin/script.php', '--hep'],
+        ];
+
+        yield 'suggestion #2' => [
+            'Unknown option --ignore-shadow-dependencies, did you mean --ignore-shadow-deps?',
+            ['bin/script.php', '--ignore-shadow-dependencies'],
+        ];
+
+        yield 'suggestion #3' => [
+            'Unknown option --composer-lock, did you mean --composer-json?',
+            ['bin/script.php', '--composer-lock'],
+        ];
+
+        yield 'suggestion #4' => [
+            'Unknown option --ignore-prod-in-dev-deps, did you mean --ignore-prod-only-in-dev-deps?',
+            ['bin/script.php', '--ignore-prod-in-dev-deps'],
+        ];
+
+        yield 'suggestion #5' => [
+            'Unknown option --ignore-dev-prod-deps, did you mean --ignore-dev-in-prod-deps?',
+            ['bin/script.php', '--ignore-dev-prod-deps'],
+        ];
+
+        yield 'no suggestion #1' => [
+            'Unknown option --vvv, see --help',
+            ['bin/script.php', '--vvv'],
+        ];
+
+        yield 'no suggestion #2' => [
+            'Unknown option --v, see --help',
+            ['bin/script.php', '--v'],
+        ];
+
+        yield 'no suggestion #3' => [
+            'Unknown option --nonsense, see --help',
+            ['bin/script.php', '--nonsense'],
+        ];
+
+        yield 'no suggestion #4' => [
+            'Unknown option --four, see --help',
+            ['bin/script.php', '--four'],
+        ];
     }
 
 }