Regex Refactoring, Removal of Buffer

phpunit.xml.dist

@@ -1,11 +1,19 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" bootstrap="./tests/bootstrap.php" colors="true" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.0/phpunit.xsd" cacheDirectory=".phpunit.cache">
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.0/phpunit.xsd"
+  cacheDirectory=".phpunit.cache"
+  failOnWarning="true"
+  colors="true"
+  bootstrap="./tests/bootstrap.php"
+  displayDetailsOnTestsThatTriggerDeprecations="true"
+  displayDetailsOnTestsThatTriggerWarnings="true"
+  displayDetailsOnTestsThatTriggerErrors="true">
   <coverage>
     <include>
       <directory suffix=".php">./src/JShrink/</directory>
     </include>
     <report>
-      <text outputFile="php://stdout" showUncoveredFiles="false"/>
+      <text outputFile="php://stdout" showUncoveredFiles="false" />
     </report>
   </coverage>
   <testsuites>
@@ -19,5 +27,5 @@
       <group>development</group>
     </exclude>
   </groups>
-  <logging/>
+  <logging />
 </phpunit>

src/JShrink/Minifier.php

@@ -74,6 +74,20 @@ class Minifier
      */
     protected $c;
 
+    /**
+     * This character is only active when certain look ahead actions take place.
+     *
+     *  @var string
+     */
+    protected $last_char;
+
+    /**
+     * This character is only active when certain look ahead actions take place.
+     *
+     *  @var string
+     */
+    protected $output;
+
     /**
      * Contains the options for the current minification process.
      *
@@ -95,6 +109,9 @@ class Minifier
      */
     protected static $defaultOptions = ['flaggedComments' => true];
 
+
+    protected static $keywords = ["delete", "do", "for", "in", "instanceof", "return", "typeof", "yield"];
+
     /**
      * Contains lock ids which are used to replace certain code patterns and
      * prevent them from being minified
@@ -115,17 +132,11 @@ class Minifier
     public static function minify($js, $options = [])
     {
         try {
-            ob_start();
-
             $jshrink = new Minifier();
             $js = $jshrink->lock($js);
-            $jshrink->minifyDirectToOutput($js, $options);
-
-            // Sometimes there's a leading new line, so we trim that out here.
-            $js = ltrim(ob_get_clean());
+            $js = ltrim($jshrink->minifyToString($js, $options));
             $js = $jshrink->unlock($js);
             unset($jshrink);
-
             return $js;
         } catch (\Exception $e) {
             if (isset($jshrink)) {
@@ -134,9 +145,6 @@ public static function minify($js, $options = [])
                 $jshrink->clean();
                 unset($jshrink);
             }
-
-            // without this call things get weird, with partially outputted js.
-            ob_end_clean();
             throw $e;
         }
     }
@@ -148,11 +156,12 @@ public static function minify($js, $options = [])
      * @param string $js      The raw javascript to be minified
      * @param array  $options Various runtime options in an associative array
      */
-    protected function minifyDirectToOutput($js, $options)
+    protected function minifyToString($js, $options)
     {
         $this->initialize($js, $options);
         $this->loop();
         $this->clean();
+        return $this->output;
     }
 
     /**
@@ -177,7 +186,9 @@ protected function initialize($js, $options)
         // Populate "a" with a new line, "b" with the first character, before
         // entering the loop
         $this->a = "\n";
-        $this->b = $this->getReal();
+        $this->b = "\n";
+        $this->last_char = "\n";
+        $this->output = "";
     }
 
     /**
@@ -192,6 +203,14 @@ protected function initialize($js, $options)
         '[' => true,
         '@' => true];
 
+
+    protected function echo($char) {
+        echo($char);
+        $this->output .= $char;
+        $this->last_char = $char[-1];
+    }
+
+
     /**
      * The primary action occurs here. This function loops through the input string,
      * outputting anything that's relevant and discarding anything that is not.
@@ -201,10 +220,11 @@ protected function loop()
         while ($this->a !== false && !is_null($this->a) && $this->a !== '') {
             switch ($this->a) {
                 // new lines
+                case "\r":
                 case "\n":
                     // if the next line is something that can't stand alone preserve the newline
                     if ($this->b !== false && isset($this->noNewLineCharacters[$this->b])) {
-                        echo $this->a;
+                        $this->echo($this->a);
                         $this->saveString();
                         break;
                     }
@@ -220,22 +240,23 @@ protected function loop()
                 // no break
                 case ' ':
                     if (static::isAlphaNumeric($this->b)) {
-                        echo $this->a;
+                        $this->echo($this->a);
                     }
 
                     $this->saveString();
                     break;
 
                 default:
                     switch ($this->b) {
+                        case "\r":
                         case "\n":
                             if (strpos('}])+-"\'', $this->a) !== false) {
-                                echo $this->a;
+                                $this->echo($this->a);
                                 $this->saveString();
                                 break;
                             } else {
                                 if (static::isAlphaNumeric($this->a)) {
-                                    echo $this->a;
+                                    $this->echo($this->a);
                                     $this->saveString();
                                 }
                             }
@@ -254,7 +275,7 @@ protected function loop()
                                 continue 3;
                             }
 
-                            echo $this->a;
+                            $this->echo($this->a);
                             $this->saveString();
                             break;
                     }
@@ -263,9 +284,20 @@ protected function loop()
             // do reg check of doom
             $this->b = $this->getReal();
 
-            if (($this->b == '/' && strpos('(,=:[!&|?', $this->a) !== false)) {
-                $this->saveRegex();
+            if ($this->b == '/') {
+                $valid_tokens = "(,=:[!&|?\n";
+                if (strpos($valid_tokens, $this->last_char) !== false || strpos($valid_tokens, $this->a) !== false) {
+                    // Regex can appear unquoted after these symbols
+                    $this->saveRegex();
+                } else if ($this->endsInKeyword()) {
+                    // This block checks for the "return" token before the slash.
+                    $this->saveRegex();
+                }
             }
+
+            // if (($this->b == '/' && strpos('(,=:[!&|?', $this->a) !== false)) {
+            //     $this->saveRegex();
+            // }
         }
     }
 
@@ -332,8 +364,25 @@ protected function getChar()
      */
     protected function peek()
     {
-        # Pull the next character but don't push the index.
-        return $this->index < $this->len ? $this->input[$this->index] : false;
+        if ($this->index >= $this->len) {
+            return false;
+        }
+
+        $char = $this->input[$this->index];
+        # Convert all line endings to unix standard.
+        # `\r\n` converts to `\n\n` and is minified.
+        if ($char == "\r") {
+            $char = "\n";
+        }
+
+        // Normalize all whitespace except for the newline character into a
+        // standard space.
+        if ($char !== "\n" && $char < "\x20") {
+            return ' ';
+        }
+
+        # Return the next character but don't push the index.
+        return $char;
     }
 
     /**
@@ -428,17 +477,17 @@ protected function processMultiLineComments($startIndex)
                 // If conditional comments or flagged comments are not the first thing in the script
                 // we need to echo a and fill it with a space before moving on.
                 if ($startIndex > 0) {
-                    echo $this->a;
+                    $this->echo($this->a);
                     $this->a = " ";
 
                     // If the comment started on a new line we let it stay on the new line
                     if ($this->input[($startIndex - 1)] === "\n") {
-                        echo "\n";
+                        $this->echo("\n");
                     }
                 }
 
                 $endPoint = ($this->index - 1) - $startIndex;
-                echo substr($this->input, $startIndex, $endPoint);
+                $this->echo(substr($this->input, $startIndex, $endPoint));
 
                 $this->c = $char;
 
@@ -504,7 +553,7 @@ protected function saveString()
         $stringType = $this->a;
 
         // Echo out that starting quote
-        echo $this->a;
+        $this->echo($this->a);
 
         // Loop until the string is done
         // Grab the very next character and load it into a
@@ -523,7 +572,7 @@ protected function saveString()
                 // block below.
                 case "\n":
                     if ($stringType === '`') {
-                        echo $this->a;
+                        $this->echo($this->a);
                     } else {
                         throw new \RuntimeException('Unclosed string at position: ' . $startpos);
                     }
@@ -543,14 +592,14 @@ protected function saveString()
                     }
 
                     // echo out the escaped character and restart the loop.
-                    echo $this->a . $this->b;
+                    $this->echo($this->a . $this->b);
                     break;
 
 
                 // Since we're not dealing with any special cases we simply
                 // output the character and continue our loop.
                 default:
-                    echo $this->a;
+                $this->echo($this->a);
             }
         }
     }
@@ -563,23 +612,23 @@ protected function saveString()
      */
     protected function saveRegex()
     {
-        echo $this->a . $this->b;
+        $this->echo($this->a . $this->b);
 
         while (($this->a = $this->getChar()) !== false) {
             if ($this->a === '/') {
                 break;
             }
 
             if ($this->a === '\\') {
-                echo $this->a;
+                $this->echo($this->a);
                 $this->a = $this->getChar();
             }
 
             if ($this->a === "\n") {
                 throw new \RuntimeException('Unclosed regex pattern at position: ' . $this->index);
             }
 
-            echo $this->a;
+            $this->echo($this->a);
         }
         $this->b = $this->getReal();
     }
@@ -595,6 +644,20 @@ protected static function isAlphaNumeric($char)
         return preg_match('/^[\w\$\pL]$/', $char) === 1 || $char == '/';
     }
 
+    protected function endsInKeyword() {
+        foreach(static::$keywords as $keyword) {
+            if (str_ends_with($this->output, $keyword)) {
+                return true;
+            }
+            if (str_ends_with($this->output, $keyword . " ")) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+
+
     /**
      * Replace patterns in the given string and store the replacement
      *

tests/Resources/jshrink/input/regex_keywords.js

@@ -0,0 +1,3 @@
+return /'/
+
+typeof /'/

tests/Resources/jshrink/input/regex_spaces.js

@@ -0,0 +1,7 @@
+function airplaneIsCarrierBased (model) {
+  return /^(FI-167|Swordfish|Fulmar|Firefly|F4F Wildcat|F6F-[35] Hellcat|Latécoère 298|A[567]M)$/.test(
+    model
+  )
+}
+
+console.log(airplaneIsCarrierBased('F6F-5 Hellcat'))

tests/Resources/jshrink/input/regex_with_quote.js

@@ -0,0 +1 @@
+/^(")$/

tests/Resources/jshrink/input/regex_with_quote_real.js

@@ -0,0 +1,3 @@
+function test (input) {
+  return /^(אחה"צ|אחרי הצהריים|בערב)$/.test(input)
+}

tests/Resources/jshrink/output/regex_keywords.js

@@ -0,0 +1,2 @@
+return /'/
+typeof /'/

tests/Resources/jshrink/output/regex_spaces.js

@@ -0,0 +1,2 @@
+function airplaneIsCarrierBased(model){return /^(FI-167|Swordfish|Fulmar|Firefly|F4F Wildcat|F6F-[35] Hellcat|Latécoère 298|A[567]M)$/.test(model)}
+console.log(airplaneIsCarrierBased('F6F-5 Hellcat'))

tests/Resources/jshrink/output/regex_with_quote.js

@@ -0,0 +1 @@
+/^(")$/

tests/Resources/jshrink/output/regex_with_quote_real.js

@@ -0,0 +1 @@
+function test(input){return /^(אחה"צ|אחרי הצהריים|בערב)$/.test(input)}