Max line per method rule

Author: martinsoenen

phpstan.neon

@@ -4,5 +4,6 @@ parameters:
     - src
 rules:
     - MartinSoenen\PHPStanRules\Rules\MaxLinePerClassRule
+    - MartinSoenen\PHPStanRules\Rules\MaxLinePerMethodRule
     - MartinSoenen\PHPStanRules\Rules\NoLaravelObserverRule
     - MartinSoenen\PHPStanRules\Rules\NoTryCatchRule

src/Rules/MaxLinePerMethodRule.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace MartinSoenen\PHPStanRules\Rules;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+
+class MaxLinePerMethodRule implements Rule
+{
+    private const int MAX_LINES = 20;
+
+    public function getNodeType(): string
+    {
+        return Node\Stmt\ClassMethod::class;
+    }
+
+    public function processNode(Node $node, Scope $scope): array
+    {
+        $startLine = $node->getStartLine() + 1;
+        $endLine = $node->getEndLine() - 1;
+        $lineCount = $endLine - $startLine;
+
+        if ($lineCount > self::MAX_LINES) {
+            return [
+                RuleErrorBuilder::message(
+                    sprintf(
+                        'The %s function has more than %d code lines. Please reduce it.',
+                        $node->name->toString(),
+                        self::MAX_LINES
+                    )
+                )
+                ->line($node->getLine())
+                ->build(),
+            ];
+        }
+
+        return [];
+    }
+}

tests/Rules/MaxLinePerMethodRuleTest.php

@@ -0,0 +1,41 @@
+<?php declare(strict_types = 1);
+
+namespace MartinSoenen\PHPStanRules\Tests\Rules;
+
+use MartinSoenen\PHPStanRules\Rules\MaxLinePerMethodRule;
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<MaxLinePerMethodRule>
+ */
+class MaxLinePerMethodRuleTest extends RuleTestCase
+{
+    protected function getRule(): \PHPStan\Rules\Rule
+    {
+        // getRule() method needs to return an instance of the tested rule
+        return new MaxLinePerMethodRule();
+    }
+
+    public function testWithMultipleLines(): void
+    {
+        // first argument: path to the example file that contains some errors that should be reported by MyRule
+        // second argument: an array of expected errors,
+        // each error consists of the asserted error message, and the asserted error file line
+        $this->analyse([__DIR__ . '/data/MaxLinePerMethodRule/MultipleLinesMethods.php'], [
+            [
+                "The twentyOneLines function has more than 20 code lines. Please reduce it.", // asserted error message
+                53, // asserted error line
+            ],
+        ]);
+    }
+
+    public function testWithOneLine(): void
+    {
+        $this->analyse([__DIR__ . '/data/MaxLinePerMethodRule/OneLineMethods.php'], []);
+    }
+
+    public function testWithNoMethods(): void
+    {
+        $this->analyse([__DIR__ . '/data/MaxLinePerMethodRule/NoMethods.php'], []);
+    }
+}

tests/Rules/data/MaxLinePerMethodRule/MultipleLinesMethods.php

@@ -0,0 +1,77 @@
+<?php
+
+namespace MartinSoenen\PHPStanRules\Tests\Rules\data\MaxLinePerMethodRule;
+
+class MultipleLinesMethods {
+    public function nineteenLines(): void
+    {
+        echo 1;
+        echo 2;
+        echo 3;
+        echo 4;
+        echo 5;
+        echo 6;
+        echo 7;
+        echo 8;
+        echo 9;
+        echo 10;
+        echo 11;
+        echo 12;
+        echo 13;
+        echo 14;
+        echo 15;
+        echo 16;
+        echo 17;
+        echo 18;
+        echo 19;
+    }
+
+    public function twentyLines(): void
+    {
+        echo 1;
+        echo 2;
+        echo 3;
+        echo 4;
+        echo 5;
+        echo 6;
+        echo 7;
+        echo 8;
+        echo 9;
+        echo 10;
+        echo 11;
+        echo 12;
+        echo 13;
+        echo 14;
+        echo 15;
+        echo 16;
+        echo 17;
+        echo 18;
+        echo 19;
+        echo 20;
+    }
+
+    public function twentyOneLines(): void
+    {
+        echo 1;
+        echo 2;
+        echo 3;
+        echo 4;
+        echo 5;
+        echo 6;
+        echo 7;
+        echo 8;
+        echo 9;
+        echo 10;
+        echo 11;
+        echo 12;
+        echo 13;
+        echo 14;
+        echo 15;
+        echo 16;
+        echo 17;
+        echo 18;
+        echo 19;
+        echo 20;
+        echo 21;
+    }
+}

tests/Rules/data/MaxLinePerMethodRule/NoMethods.php

@@ -0,0 +1,6 @@
+<?php
+
+namespace MartinSoenen\PHPStanRules\Tests\Rules\data\MaxLinePerMethodRule;
+
+class NoMethods {
+}

tests/Rules/data/MaxLinePerMethodRule/OneLineMethods.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace MartinSoenen\PHPStanRules\Tests\Rules\data\MaxLinePerMethodRule;
+
+class OneLineMethods {
+    public function oneLine(): void
+    {
+        echo 1;
+    }
+
+    public function anotherOneLine(): void
+    {
+        echo 1;
+    }
+}