add tests on the ComponentMapper for a future refacto

app/Presenter/Analyze/Component/Shared/Component.php

@@ -25,7 +25,7 @@ public function countClasses(): int
         return $this->countClasses;
     }
 
-    public function countAbstractions(): float
+    public function countAbstractions(): int
     {
         return $this->countAbstractions;
     }

app/Presenter/Analyze/Component/Shared/ComponentMapper.php

@@ -49,8 +49,8 @@ public function from(array $metrics): array
                 $component,
                 count($componentMetrics),
                 $abstract,
-                $abstract / count($componentMetrics),
-                $instability / count($componentMetrics),
+                $abstract / (count($componentMetrics) ?: 1),
+                $instability / (count($componentMetrics) ?: 1),
                 $innerDependencies,
             );
         }

tests/Builders/AnalyzeMetricBuilder.php

@@ -22,6 +22,13 @@ public function withName(string $value): self
         return $this;
     }
 
+    public function isAbstract(): self
+    {
+        $this->abstract = true;
+
+        return $this;
+    }
+
     public function withDependencies(array $value): self
     {
         $this->dependencies = $value;

tests/Unit/Presenter/ComponentMapperTest.php

@@ -0,0 +1,102 @@
+<?php
+
+use App\Presenter\Analyze\Component\Shared\Component;
+use App\Presenter\Analyze\Component\Shared\ComponentMapper;
+
+it('should map metrics to components', function () {
+
+    $mapper = new ComponentMapper();
+
+    $metrics = [
+        'A' => [
+            $this->oneAnalyzeMetric()->withName('A\Class1')->build(),
+            $this->oneAnalyzeMetric()->withName('A\Class2')->build(),
+            $this->oneAnalyzeMetric()->withName('A\Class3')->build(),
+        ]
+    ];
+
+    $components = $mapper->from($metrics);
+
+    expect($components)->toHaveCount(1);
+    expect($components[0])->toBeInstanceOf(Component::class);
+    expect($components[0]->name())->toBe('A');
+});
+
+it('should map metrics to components with dependencies', function () {
+
+    $mapper = new ComponentMapper();
+
+    $metrics = [
+        'A' => [
+            $this->oneAnalyzeMetric()->withName('A\Class1')->withDependencies(['B\Class2'])->build(),
+        ], 
+        'B' => [
+            //
+        ]
+    ];
+
+    $components = $mapper->from($metrics);
+
+    expect($components)->toHaveCount(2);
+    expect($components[0]->dependencies())->toBe(['B']);
+
+});
+
+it('should not keep dependencies from unwanted namespaces', function () {
+
+    $mapper = new ComponentMapper();
+
+    $metrics = [
+        'A' => [
+            /**
+             * This dependency is in an unwanted namespace C
+             */
+            $this->oneAnalyzeMetric()->withName('A\Class1')->withDependencies(['C\Class2'])->build(),
+        ],
+        'B' => [
+            //
+        ]
+    ];
+
+    $components = $mapper->from($metrics);
+
+    expect($components)->toHaveCount(2);
+    expect($components[0]->dependencies())->toBe([]);
+});
+
+it('should calculate the average abstractness', function () {
+
+    $mapper = new ComponentMapper();
+
+    $metrics = [
+        'A' => [
+            $this->oneAnalyzeMetric()->build(),
+            $this->oneAnalyzeMetric()->isAbstract()->build(),
+            $this->oneAnalyzeMetric()->isAbstract()->build(),
+            $this->oneAnalyzeMetric()->isAbstract()->build(),
+        ],
+    ];
+
+    $components = $mapper->from($metrics);
+
+    expect($components[0]->countClasses())->toBe(4);
+    expect($components[0]->countAbstractions())->toBe(3);
+    expect($components[0]->abstractness())->toBe(0.75);
+});
+
+it('should calculate the average instability', function () {
+
+    $mapper = new ComponentMapper();
+
+    $metrics = [
+        'A' => [
+            $this->oneAnalyzeMetric()->withInstability(0.3)->build(),
+            $this->oneAnalyzeMetric()->withInstability(0.7)->build(),
+            $this->oneAnalyzeMetric()->withInstability(1)->build(),
+        ],
+    ];
+
+    $components = $mapper->from($metrics);
+
+    expect($components[0]->instability())->toBe(0.67);
+});