Adds argument suggestion support for unknown arguments

src/Argument/Manager.php

@@ -258,4 +258,24 @@ public function trailingArray()
     {
         return $this->parser->trailingArray();
     }
+
+    /**
+     * Returns the list of unknown prefixed arguments and their suggestions.
+     *
+     * @return array The list of unknown prefixed arguments and their suggestions.
+     */
+    public function getUnknowPrefixedArgumentsAndSuggestions()
+    {
+        return $this->parser->getUnknowPrefixedArgumentsAndSuggestions();
+    }
+
+    /**
+     * Sets the minimum similarity percentage for finding suggestions.
+     *
+     * @param float $percentage The minimum similarity percentage to set.
+     */
+    public function setMinimumSimilarityPercentage(float $percentage)
+    {
+        $this->parser->setMinimumSimilarityPercentage($percentage);
+    }
 }

src/Argument/Parser.php

@@ -24,6 +24,23 @@ class Parser
 
     protected $trailingArray;
 
+    /**
+     * List of unknown arguments and best argument suggestion.
+     *
+     * The key corresponds to the unknown argument and the value to the
+     * argument suggestion, if any.
+     *
+     * @var array
+     */
+    protected $unknowPrefixedArguments = [];
+
+    /**
+     * Minimum similarity percentage to detect similar arguments.
+     *
+     * @var float
+     */
+    protected $minimumSimilarityPercentage = 0.6;
+
     public function __construct()
     {
         $this->summary = new Summary();
@@ -61,6 +78,10 @@ public function parse(array $argv = null)
 
         $unParsedArguments = $this->prefixedArguments($cliArguments);
 
+        // Searches for unknown prefixed arguments and finds a suggestion
+        // within the list of valid arguments.
+        $this->unknowPrefixedArguments($unParsedArguments);
+
         $this->nonPrefixedArguments($unParsedArguments);
 
         // After parsing find out which arguments were required but not
@@ -306,4 +327,98 @@ protected function getCommandAndArguments(array $argv = null)
 
         return compact('arguments', 'command');
     }
+
+    /**
+     * Processes unknown prefixed arguments and sets suggestions if no matching
+     * prefix is found.
+     *
+     * @param array $unParsedArguments The array of unparsed arguments to
+     * process.
+     */
+    protected function unknowPrefixedArguments(array $unParsedArguments)
+    {
+        foreach ($unParsedArguments as $arg) {
+            $unknowArgumentName = $this->getUnknowArgumentName($arg);
+            if (!$this->findPrefixedArgument($unknowArgumentName)) {
+                if (is_null($unknowArgumentName)) {
+                    continue;
+                }
+                $suggestion = $this->findSuggestionsForUnknowPrefixedArguments(
+                    $unknowArgumentName,
+                    $this->filter->withPrefix()
+                );
+                $this->setSuggestion($unknowArgumentName, $suggestion);
+            }
+        }
+    }
+
+    /**
+     * Sets the suggestion for an unknown argument name.
+     *
+     * @param string $unknowArgName The name of the unknown argument.
+     * @param string $suggestion The suggestion for the unknown argument.
+     */
+    protected function setSuggestion(string $unknowArgName, string $suggestion)
+    {
+        $this->unknowPrefixedArguments[$unknowArgName] = $suggestion;
+    }
+
+    /**
+     * Extracts the unknown argument name from a given argument string.
+     *
+     * @param string $arg The argument string to process.
+     * @return string|null The extracted unknown argument name or null if not
+     * found.
+     */
+    protected function getUnknowArgumentName(string $arg)
+    {
+        if (preg_match('/^[-]{1,2}([^-]+?)(?:=|$)/', $arg, $matches)) {
+            return $matches[1];
+        }
+        return null;
+    }
+
+    /**
+     * Finds the most similar known argument for an unknown prefixed argument.
+     *
+     * @param string $argName The name of the unknown argument to find
+     * suggestions for.
+     * @param array $argList The list of known arguments to compare against.
+     * @return string The most similar known argument name.
+     */
+    protected function findSuggestionsForUnknowPrefixedArguments(
+        string $argName,
+        array $argList
+    ) {
+        $mostSimilar = '';
+        $greatestSimilarity = $this->minimumSimilarityPercentage * 100;
+        foreach ($argList as $arg) {
+            similar_text($argName, $arg->name(), $percent);
+            if ($percent > $greatestSimilarity) {
+                $greatestSimilarity = $percent;
+                $mostSimilar = $arg->name();
+            }
+        }
+        return $mostSimilar;
+    }
+
+    /**
+     * Returns the list of unknown prefixed arguments and their suggestions.
+     *
+     * @return array The list of unknown prefixed arguments and their suggestions.
+     */
+    public function getUnknowPrefixedArgumentsAndSuggestions()
+    {
+        return $this->unknowPrefixedArguments;
+    }
+
+    /**
+     * Sets the minimum similarity percentage for finding suggestions.
+     *
+     * @param float $percentage The minimum similarity percentage to set.
+     */
+    public function setMinimumSimilarityPercentage(float $percentage)
+    {
+        $this->minimumSimilarityPercentage = $percentage;
+    }
 }

tests/Argument/ManagerTest.php

@@ -70,4 +70,36 @@ public function testItStoresTrailingInArray()
         $this->assertEquals('test trailing with spaces', $this->manager->trailing());
         $this->assertEquals(['test', 'trailing with spaces'], $this->manager->trailingArray());
     }
+
+    public function testItSuggestAlternativesToUnknowArguments()
+    {
+        $this->manager->add([
+            'user' => [
+                'longPrefix' => 'user',
+            ],
+            'password' => [
+                'longPrefix' => 'password',
+            ],
+            'flag' => [
+                'longPrefix' => 'flag',
+                'noValue'    => true,
+            ],
+        ]);
+
+        $argv = [
+            'test-script',
+            '--user=baz',
+            '--pass=123',
+            '--fag',
+            '--xyz',
+        ];
+
+        $this->manager->parse($argv);
+        $processed = $this->manager->getUnknowPrefixedArgumentsAndSuggestions();
+
+        $this->assertCount(3, $processed);
+        $this->assertEquals('password', $processed['pass']);
+        $this->assertEquals('flag', $processed['fag']);
+        $this->assertEquals('', $processed['xyz']);
+    }
 }