Add guidelines and tests for implementing PHP interfaces

Introduce `guidelines.md` for development standards and project setup. Add tests for `MoodlePHPNewClassAction` to validate PHP interface implementation. Update implementation logic to handle `implements` clause modifications.

Author: AviMoto

.junie/guidelines.md

@@ -0,0 +1,74 @@
+# Moodle Plugin Development Guidelines
+
+## Project Overview
+This is an IntelliJ Platform plugin project for Moodle development support.
+
+## Tech Stack
+- Kotlin
+- Gradle (with Kotlin DSL)
+- IntelliJ Platform SDK
+- JUnit for testing
+- Kover for code coverage
+- Qodana for code quality
+
+## Project Structure
+```
+.
+├── src/
+│   ├── main/kotlin/      # Source code
+│   ├── main/resources/   # Resources (icons, templates)
+│   │   └── META-INF/    # Plugin configuration
+│   └── test/            # Test files
+├── .run/                # Run configurations
+├── build.gradle.kts     # Gradle build configuration
+├── gradle.properties    # Gradle properties
+├── qodana.yml          # Code quality settings
+└── README.md           # Project documentation
+```
+
+## Configuration Files
+- `src/main/resources/META-INF/plugin.xml`: Core plugin configuration
+- `qodana.yml`: Code quality analysis settings
+- `gradle.properties`: Gradle and plugin properties
+- `.run/`: IDE run configurations
+
+## Build & Run
+1. Setup:
+   ```bash
+   ./gradlew clean
+   ```
+2. Build:
+   ```bash
+   ./gradlew build
+   ```
+3. Run IDE with plugin:
+   ```bash
+   ./gradlew runIde
+   ```
+
+## Testing
+- Run tests:
+  ```bash
+  ./gradlew test
+  ```
+- Run with coverage:
+  ```bash
+  ./gradlew koverReport
+  ```
+- UI Tests:
+  ```bash
+  ./gradlew runIdeForUiTests
+  ```
+
+## Development Guidelines
+1. Use Kotlin coding conventions
+2. Add tests for new features
+3. Update CHANGELOG.md for changes
+4. Follow semantic versioning
+5. Keep plugin.xml up to date
+
+## Useful Commands
+- Clean and build: `./gradlew clean build`
+- Run plugin verifier: `./gradlew runPluginVerifier`
+- Generate coverage report: `./gradlew koverReport`
+- Publish plugin: `./gradlew publishPlugin`

src/main/kotlin/il/co/sysbind/intellij/moodledev/actions/generation/MoodlePHPNewClassAction.kt

@@ -20,10 +20,10 @@ import com.jetbrains.php.lang.PhpLangUtil
 import com.jetbrains.php.lang.inspections.classes.PhpAddMethodStubsQuickFix
 import com.jetbrains.php.lang.intentions.PhpImportClassIntention
 import com.jetbrains.php.lang.psi.PhpGroupUseElement.PhpUseKeyword
+import com.jetbrains.php.lang.psi.PhpPsiElementFactory
 import com.jetbrains.php.lang.psi.elements.Method
 import com.jetbrains.php.lang.psi.elements.PhpClass
 import com.jetbrains.php.lang.psi.elements.PhpPsiElement
-import com.jetbrains.php.refactoring.extract.extractInterface.PhpExtractInterfaceProcessor
 import com.jetbrains.php.templates.PhpCreateFileFromTemplateDataProvider
 import com.jetbrains.php.templates.PhpTemplatesSettings
 import il.co.sysbind.intellij.moodledev.project.MoodleProjectSettings
@@ -178,7 +178,12 @@ class MoodlePHPNewClassAction : PhpNewBaseAction(CAPTION, "", PhpFileType.INSTAN
             if (!StringUtil.isEmpty(interfaceToImplement) && implementedInterfaces.add(interfaceFqn)) {
                 val interfaceQualifiedName =
                     if (scope != null) PhpCodeInsightUtil.createQualifiedName(scope, interfaceFqn) else interfaceFqn
-                PhpExtractInterfaceProcessor.addImplementClause(project, phpClass, interfaceQualifiedName)
+                val implementsClause = PhpPsiElementFactory.createImplementsList(project, interfaceQualifiedName)
+                if (phpClass.implementsList != null) {
+                    phpClass.implementsList!!.add(implementsClause)
+                } else {
+                    phpClass.add(implementsClause)
+                }
                 if (PhpReferenceInsertHandler.shouldInsertImport(phpClass, phpClass, interfaceFqn)) {
                     PhpImportClassIntention.apply(
                         project,
@@ -206,4 +211,4 @@ class MoodlePHPNewClassAction : PhpNewBaseAction(CAPTION, "", PhpFileType.INSTAN
             phpClass.methods
         ) { method: Method -> method.isAbstract && method.containingClass !== phpClass }
     }
-}
+}

src/test/kotlin/il/co/sysbind/intellij/moodledev/actions/generation/MoodlePHPNewClassActionTest.kt

@@ -0,0 +1,49 @@
+package il.co.sysbind.intellij.moodledev.actions.generation
+
+import com.intellij.openapi.command.WriteCommandAction
+import com.intellij.psi.PsiFile
+import com.intellij.psi.util.PsiTreeUtil
+import com.intellij.testFramework.fixtures.BasePlatformTestCase
+import com.jetbrains.php.lang.psi.elements.PhpClass
+import com.jetbrains.php.lang.psi.elements.PhpPsiElement
+
+class MoodlePHPNewClassActionTest : BasePlatformTestCase() {
+    fun testImplementInterfaces() {
+        // Create a PHP file with a class
+        val phpFile = myFixture.configureByText(
+            "test.php",
+            """<?php
+            class TestClass {
+            }
+            """
+        )
+
+        // Get the class from the file
+        val phpClass = PsiTreeUtil.findChildOfType(phpFile, PhpClass::class.java)
+        assertNotNull("PHP class should be created", phpClass)
+
+        // Create an instance of MoodlePHPNewClassAction
+        val action = MoodlePHPNewClassAction()
+
+        // Call implementInterfaces through reflection since it's private
+        val method = MoodlePHPNewClassAction::class.java.getDeclaredMethod(
+            "implementInterfaces",
+            PhpClass::class.java,
+            PhpPsiElement::class.java,
+            Collection::class.java
+        )
+        method.isAccessible = true
+
+        // Test implementing an interface
+        WriteCommandAction.runWriteCommandAction(project) {
+            method.invoke(action, phpClass, phpClass, listOf("\\TestInterface"))
+        }
+
+        // Verify the interface was added
+        assertEquals(
+            "Interface should be implemented",
+            "\\TestInterface",
+            phpClass?.implementsList?.referenceElements?.firstOrNull()?.fqn
+        )
+    }
+}