Report dead dependencies

README.md

@@ -1,13 +1,19 @@
 # Composer dependency analyser
 
-This package aims to detect composer dependency issues in your project, fast!
+This package aims to detect composer dependency issues in your project.
 
-For example, it detects shadowed depencencies similar to [maglnet/composer-require-checker](https://github.com/maglnet/ComposerRequireChecker), but **much faster**:
+It detects **shadowed dependencies** and **dead dependencies** similar to other tools, but **MUCH faster**:
 
-| Project                               | Analysis of 13k files |
-|---------------------------------------|-----------------------|
-| shipmonk/composer-dependency-analyser | 2 secs                |
-| maglnet/composer-require-checker      | 124 secs              |
+| Project                                   | Dead dependency  | Shadow dependency | Time*       |
+|-------------------------------------------|------------------|-------------------|-------------|
+| maglnet/composer-require-checker          | ❌                | ✅                 | 124 secs |
+| icanhazstring/composer-unused             | ✅                | ❌                 | 72 secs  |
+| **shipmonk/composer-dependency-analyser** | ✅                | ✅                 | **3 secs** |
+
+<sup><sub>\*Time measured on codebase with ~13 000 files</sub></sup>
+
+
+This means you can safely add this tool to CI without wasting resources.
 
 ## Installation:
 
@@ -38,17 +44,19 @@ Found shadow dependencies!
 
 You can add `--verbose` flag to see first usage (file & line) of each class.
 
-## What it does:
+## Detected issues:
 This tool reads your `composer.json` and scans all paths listed in both `autoload` sections while analysing:
 
-- Shadowed dependencies
+- **Shadowed dependencies**
   - Those are dependencies of your dependencies, which are not listed in `composer.json`
   - Your code can break when your direct dependency gets updated to newer version which does not require that shadowed dependency anymore
   - You should list all those classes within your dependencies
-- Dev dependencies used in production code
+- **Unused dependencies**
+  - Any non-dev dependency is expected to have at least single usage within the scanned paths
+- **Dev dependencies in production code**
   - Your code can break once you run your application with `composer install --no-dev`
   - You should move those to `require` from `require-dev`
-- Unknown classes
+- **Unknown classes**
   - Any class missing in composer classmap gets reported as we cannot say if that one is shadowed or not
   - This might be expected in some cases, so you can disable this behaviour by `--ignore-unknown-classes`
 
@@ -57,9 +65,6 @@ If you want to run it elsewhere, you can use `--composer-json=path/to/composer.j
 
 Currently, it only supports those autoload sections: `psr-4`, `psr-0`, `files`.
 
-## Future scope:
-- Detecting dead dependencies
-
 ## Limitations:
 - Files without namespace has limited support
   - Only classes with use statements and FQNs are detected

src/ClassUsage.php

@@ -0,0 +1,45 @@
+<?php declare(strict_types = 1);
+
+namespace ShipMonk\Composer;
+
+class ClassUsage
+{
+
+    /**
+     * @var string
+     */
+    private $classname;
+
+    /**
+     * @var string
+     */
+    private $filepath;
+
+    /**
+     * @var int
+     */
+    private $lineNumber;
+
+    public function __construct(string $classname, string $filepath, int $lineNumber)
+    {
+        $this->classname = $classname;
+        $this->filepath = $filepath;
+        $this->lineNumber = $lineNumber;
+    }
+
+    public function getClassname(): string
+    {
+        return $this->classname;
+    }
+
+    public function getFilepath(): string
+    {
+        return $this->filepath;
+    }
+
+    public function getLineNumber(): int
+    {
+        return $this->lineNumber;
+    }
+
+}

src/ComposerDependencyAnalyser.php

@@ -12,20 +12,26 @@
 use ShipMonk\Composer\Error\DevDependencyInProductionCodeError;
 use ShipMonk\Composer\Error\ShadowDependencyError;
 use ShipMonk\Composer\Error\SymbolError;
+use ShipMonk\Composer\Error\UnusedDependencyError;
 use UnexpectedValueException;
+use function array_diff;
+use function array_filter;
+use function array_keys;
+use function array_values;
 use function class_exists;
 use function defined;
 use function explode;
 use function file_get_contents;
 use function function_exists;
+use function get_class;
 use function interface_exists;
 use function is_file;
-use function ksort;
 use function realpath;
 use function str_replace;
 use function strlen;
 use function substr;
 use function trim;
+use function usort;
 use const DIRECTORY_SEPARATOR;
 
 class ComposerDependencyAnalyser
@@ -80,11 +86,12 @@ public function __construct(
 
     /**
      * @param array<string, bool> $scanPaths path => is dev path
-     * @return array<string, SymbolError>
+     * @return list<SymbolError>
      */
     public function scan(array $scanPaths): array
     {
         $errors = [];
+        $usedPackages = [];
 
         foreach ($scanPaths as $scanPath => $isDevPath) {
             foreach ($this->listPhpFilesIn($scanPath) as $filePath) {
@@ -99,7 +106,7 @@ public function scan(array $scanPaths): array
 
                     if (!isset($this->optimizedClassmap[$usedSymbol])) {
                         if (!$this->isConstOrFunction($usedSymbol)) {
-                            $errors[$usedSymbol] = new ClassmapEntryMissingError($usedSymbol, $filePath, $lineNumber);
+                            $errors[$usedSymbol] = new ClassmapEntryMissingError(new ClassUsage($usedSymbol, $filePath, $lineNumber));
                         }
 
                         continue;
@@ -114,19 +121,40 @@ public function scan(array $scanPaths): array
                     $packageName = $this->getPackageNameFromVendorPath($classmapPath);
 
                     if ($this->isShadowDependency($packageName)) {
-                        $errors[$usedSymbol] = new ShadowDependencyError($usedSymbol, $packageName, $filePath, $lineNumber);
+                        $errors[$packageName] = new ShadowDependencyError($packageName, new ClassUsage($usedSymbol, $filePath, $lineNumber));
                     }
 
                     if (!$isDevPath && $this->isDevDependency($packageName)) {
-                        $errors[$usedSymbol] = new DevDependencyInProductionCodeError($usedSymbol, $packageName, $filePath, $lineNumber);
+                        $errors[$packageName] = new DevDependencyInProductionCodeError($packageName, new ClassUsage($usedSymbol, $filePath, $lineNumber));
                     }
+
+                    $usedPackages[$packageName] = true;
                 }
             }
         }
 
-        ksort($errors);
+        $unusedDependencies = array_diff(
+            array_keys(array_filter($this->composerJsonDependencies, static function (bool $devDependency) {
+                return !$devDependency; // dev deps are typically used only in CI
+            })),
+            array_keys($usedPackages)
+        );
+
+        foreach ($unusedDependencies as $unusedDependency) {
+            $errors[] = new UnusedDependencyError($unusedDependency);
+        }
 
-        return $errors;
+        usort($errors, static function (SymbolError $a, SymbolError $b): int {
+            return [
+                get_class($a),
+                $a->getPackageName() ?? '',
+            ] <=> [
+                get_class($b),
+                $b->getPackageName() ?? '',
+            ];
+        });
+
+        return array_values($errors);
     }
 
     private function isShadowDependency(string $packageName): bool

src/Error/ClassmapEntryMissingError.php

@@ -2,53 +2,31 @@
 
 namespace ShipMonk\Composer\Error;
 
+use ShipMonk\Composer\ClassUsage;
+
 class ClassmapEntryMissingError implements SymbolError
 {
 
     /**
-     * @var string
-     */
-    private $className;
-
-    /**
-     * @var string
-     */
-    private $exampleUsageFilepath;
-
-    /**
-     * @var int
+     * @var ClassUsage
      */
-    private $exampleUsageLine;
+    private $exampleUsage;
 
     public function __construct(
-        string $className,
-        string $exampleUsageFilepath,
-        int $exampleUsageLine
+        ClassUsage $exampleUsage
     )
     {
-        $this->className = $className;
-        $this->exampleUsageFilepath = $exampleUsageFilepath;
-        $this->exampleUsageLine = $exampleUsageLine;
-    }
-
-    public function getSymbolName(): string
-    {
-        return $this->className;
-    }
-
-    public function getExampleUsageFilepath(): string
-    {
-        return $this->exampleUsageFilepath;
+        $this->exampleUsage = $exampleUsage;
     }
 
     public function getPackageName(): ?string
     {
         return null;
     }
 
-    public function getExampleUsageLine(): int
+    public function getExampleUsage(): ClassUsage
     {
-        return $this->exampleUsageLine;
+        return $this->exampleUsage;
     }
 
 }

src/Error/DevDependencyInProductionCodeError.php

@@ -2,60 +2,38 @@
 
 namespace ShipMonk\Composer\Error;
 
+use ShipMonk\Composer\ClassUsage;
+
 class DevDependencyInProductionCodeError implements SymbolError
 {
 
-    /**
-     * @var string
-     */
-    private $className;
-
     /**
      * @var string
      */
     private $packageName;
 
     /**
-     * @var string
+     * @var ClassUsage
      */
-    private $exampleUsageFilepath;
-
-    /**
-     * @var int
-     */
-    private $exampleUsageLine;
+    private $exampleUsage;
 
     public function __construct(
-        string $className,
         string $packageName,
-        string $exampleUsageFilepath,
-        int $exampleUsageLine
+        ClassUsage $exampleUsage
     )
     {
-        $this->className = $className;
         $this->packageName = $packageName;
-        $this->exampleUsageFilepath = $exampleUsageFilepath;
-        $this->exampleUsageLine = $exampleUsageLine;
+        $this->exampleUsage = $exampleUsage;
     }
 
     public function getPackageName(): string
     {
         return $this->packageName;
     }
 
-    public function getSymbolName(): string
-    {
-        return $this->className;
-    }
-
-    public function getExampleUsageFilepath(): string
-    {
-        return $this->exampleUsageFilepath;
-    }
-
-    public function getExampleUsageLine(): int
+    public function getExampleUsage(): ClassUsage
     {
-        return $this->exampleUsageLine;
+        return $this->exampleUsage;
     }
 
 }