Merge pull request #5 from smeghead/feature/parse-asign

feat: When determining the local variable severity, the coefficients …

Author: smeghead

CHANGELOG.md

@@ -1,5 +1,9 @@
 # CHANGELOG
 
+### Features
+
+ * When determining the local variable severity, the coefficients are now taken into account when the variable is an assignment.
+
 ### Bug fix
 
  * Refactor remove interface Scope

README.md

@@ -41,7 +41,7 @@ composer require --dev smeghead/php-variable-hard-usage
 ```
 
 ## Usage
-
+66 + 32 + 66
 If you specify the path of the file for which you want to measure the local variable abuse and run the program, a report will be displayed in JSON format.
 
 ```bash
@@ -84,4 +84,40 @@ $ vendor/bin/php-variable-hard-usage somewhere/your-php-file.php
 }
 ```
 
+## How to calculate VariableHardUsage
+
+VariableHardUsage is an index used to evaluate the frequency of use and scope of a local variable within a function. This indicator is calculated based on the variance of the line number at which the variable is used and the frequency with which the variable is assigned.
+
+### Calculation Procedure
+
+1. Obtain the line numbers of the variables:.
+
+  * Obtains the line numbers of all variables used in the function.
+
+2. Calculate the average of the line numbers.
+
+  * Calculates the average of the retrieved line numbers. This is obtained by dividing the sum of the line numbers by the number of variables.
+
+3. Calculate VariableHardUsage.
+
+  * For each variable, the absolute difference between the line number and the average line number is calculated.
+  * If a variable is assigned, the difference is multiplied by a factor (2 by default).
+  * Sum all these values to obtain VariableHardUsage.
+
+### EXAMPLE.
+
+For example, suppose there are three variables in a function, each with row numbers 10, 20, and 30, and that some assignments are made and some are not made. In this case, the average row number is 20.
+
+* Variable A: Row 10, with assignment
+* Variable B: Row 20, no assignment
+* Variable C: Row 30, with assignment
+
+In this case, VariableHardUsage is calculated as follows
+
+* Variable A: |10 - 20| * 2 = 20
+* Variable B: |20 - 20| * 1 = 0
+* Variable C: |30 - 20| * 2 = 20
+
+Summing these, VariableHardUsage is 20 + 0 + 20 = 40.
 
+VariableHardUsage is thus calculated as a measure of the frequency of use and scope of a variable. This metric can be used to quantitatively evaluate the usage of local variables within a function and help improve code readability and maintainability.

src/Analyze/VariableAnalyzer.php

@@ -9,6 +9,8 @@
 
 final class VariableAnalyzer
 {
+    private const ASSIGNED_VARIABLE_COEFFICIENT = 2;
+
     /**
      * @var list<Func>
      */
@@ -50,7 +52,7 @@ private function calcVariableHardUsage(array $vars): int
     {
         $lineNumbers = array_map(fn($var) => $var->lineNumber, $vars);
         $avarageLinuNumber = intval(array_sum($lineNumbers) / count($lineNumbers));
-        $variableHardUsage = array_sum(array_map(fn($lineNumber) => abs($lineNumber - $avarageLinuNumber), $lineNumbers));
+        $variableHardUsage = array_sum(array_map(fn(VarReference $var) => abs($var->lineNumber - $avarageLinuNumber) * ($var->assigned ? self::ASSIGNED_VARIABLE_COEFFICIENT : 1), $vars));
         return $variableHardUsage;
     }
 }

src/Parse/VarReference.php

@@ -9,7 +9,7 @@ final class VarReference
     public function __construct(
         public readonly string $name,
         public readonly int $lineNumber,
-        public readonly bool $updated = false
+        public readonly bool $assigned = false
     )
     {
     }

src/Parse/VariableParser.php

@@ -75,7 +75,8 @@ private function collectParseResultPerFunctionLike(array $functionLikes): array
 
             $variables = $this->nodeFinder->findInstanceOf($function, Variable::class);
             foreach ($variables as $variable) {
-                $func->addVariable(new VarReference($variable->name, $variable->getLine())); // @phpstan-ignore-line
+                $assigned = $variable->getAttribute('assigned');
+                $func->addVariable(new VarReference($variable->name, $variable->getLine(), $assigned === true)); // @phpstan-ignore-line
             }
             return $func;
         }, $functionLikes);

src/Parse/Visitor/FunctionLikeFindingVisitor.php

@@ -5,6 +5,7 @@
 namespace Smeghead\PhpVariableHardUsage\Parse\Visitor;
 
 use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
 use PhpParser\Node\FunctionLike;
 use PhpParser\NodeVisitor\FindingVisitor;
 use PhpParser\Node\Stmt\Class_;
@@ -30,6 +31,9 @@ public function enterNode(Node $node) {
             $this->currentNamespace = $node->name ? $node->name->name : null;
         }
 
+        if ($node instanceof Assign) {
+            $node->var->setAttribute('assigned', true); // Mark as assigned
+        }
         if ($node instanceof FunctionLike) {
             $node->setAttribute('namespace', $this->currentNamespace);
         }

test/VariableAnalizerTest.php

@@ -42,4 +42,22 @@ public function testAnalyzeFunctionLong(): void
         // abs(34 - 1) + abs(34 - 2) + abs(34 - 100) = 33 + 32 + 66 = 131
         $this->assertSame(131, $scopes[0]->getAnalyzedVariables()[0]->variableHardUsage);
     }
+
+    public function testAnalyzeFunctionLongAssignedVariable(): void
+    {
+        $func = new Func(null, 'testFunction');
+        $func->addVariable(new VarReference('a', 1, true));
+        $func->addVariable(new VarReference('a', 2));
+        $func->addVariable(new VarReference('a', 100));
+
+        $sut = new VariableAnalyzer([$func]);
+        $result = $sut->analyze();
+        $scopes = $result->scopes;
+
+        $this->assertCount(1, $scopes);
+        $this->assertSame('testFunction', $scopes[0]->name);
+        // (1 + 2 + 100) / 3 = 34
+        // abs(34 - 1) * 2 + abs(34 - 2) + abs(34 - 100) = 66 + 32 + 66 = 164
+        $this->assertSame(164, $scopes[0]->getAnalyzedVariables()[0]->variableHardUsage);
+    }
 }

test/VariableParserTest.php

@@ -26,8 +26,10 @@ public function testParseFunction(): void
         $vars = $functions[0]->getVariables();
         $this->assertSame('num', $vars[0]->name);
         $this->assertSame(5, $vars[0]->lineNumber, 'first $num (5)');
+        $this->assertSame(true, $vars[0]->assigned, 'first $num (5) asign');
         $this->assertSame('num', $vars[1]->name);
         $this->assertSame(10, $vars[1]->lineNumber, 'second $num (10)');
+        $this->assertSame(false, $vars[1]->assigned, 'second $num (10) not reference');
     }
 
     public function testParseClass(): void

test/fixtures/sample_functions.php

@@ -0,0 +1,47 @@
+<?php
+
+// 酷使する関数
+function hardWordCount(string $text): int {
+    $wordCount = 0;
+    $currentWord = '';
+    for ($i = 0; $i < strlen($text); $i++) {
+        if ($text[$i] === ' ') {
+            if ($currentWord !== '') {
+                $wordCount++;
+                $currentWord = '';
+            }
+        } else {
+            $currentWord .= $text[$i];
+        }
+    }
+    if ($currentWord !== '') {
+        $wordCount++;
+    }
+    return $wordCount;
+}
+
+// あまり酷使しない関数
+function lightWordCount(string $text): int {
+    $words = explode(' ', $text);
+    $wordCount = 0;
+    foreach ($words as $word) {
+        if ($word !== '') {
+            $wordCount++;
+        }
+    }
+    return $wordCount;
+}
+
+// 全然酷使しない関数
+function niceWordCount(string $text): int {
+    return count(array_filter(explode(' ', $text), fn($word) => $word !== ''));
+}
+
+
+
+
+$text = 'This is a pen.';
+
+echo hardWordCount($text) . PHP_EOL;
+echo lightWordCount($text) . PHP_EOL;
+echo niceWordCount($text) . PHP_EOL;