fix(java): improve symbol resolution logic #101

Improve symbol resolution by handling package names, class names, method names, and their combinations, as per the requested logic.

Refactored the `JavaCustomDevInsSymbolProvider.kt` file to handle symbol resolution according to package names, class names, method names, and combinations of these. Also, updated the `quick-start.md` file with an example of the method output.

Author: phodal

docs/devins/quick-start.md

@@ -79,3 +79,20 @@ The output will be:
     cc.unitmesh.untitled.demo.MathHelperTest
     cc.unitmesh.untitled.demo.DemoApplicationTests
     ```
+
+Get method will return code:
+
+    /symbol:cc.unitmesh.untitled.demo.MathHelper.calculateInsurance
+
+The output will be:
+
+    ```java
+    public static double calculateInsurance(double income) {
+        if (income <= 10000) {
+            return income * 0.365;
+        } else {
+            return income * 0.365 + 1000;
+        }
+    }
+    ```
+

java/src/main/kotlin/cc/unitmesh/idea/provider/JavaCustomDevInsSymbolProvider.kt

@@ -54,25 +54,59 @@ class JavaCustomDevInsSymbolProvider : DevInsSymbolProvider {
     override fun resolveSymbol(project: Project, symbol: String): Iterable<String> {
         val scope = GlobalSearchScope.allScope(project)
 
+        if (symbol.isEmpty()) return emptyList()
+
+        // className only, like `String` not Dot
+        if (symbol.contains(".").not()) {
+            val psiClasses = PsiShortNamesCache.getInstance(project).getClassesByName(symbol, scope)
+            if (psiClasses.isNotEmpty()) {
+                return psiClasses.map { it.qualifiedName!! }
+            }
+        }
+
         // for package name only, like `cc.unitmesh`
         JavaFileManagerImpl(project).findPackage(symbol)?.let { pkg ->
             return pkg.classes.map { it.qualifiedName!! }
         }
 
-        // for class name only, like `cc.unitmesh.idea.provider.JavaCustomDevInsSymbolProvider`
-        val psiClasses = PsiShortNamesCache.getInstance(project).getClassesByName(symbol, scope)
-        if (psiClasses.isNotEmpty()) {
-            return psiClasses.map { it.qualifiedName!! }
-        }
-
         // for single class, with function name, like `cc.unitmesh.idea.provider.JavaCustomDevInsSymbolProvider`
         val clazz = JavaFileManagerImpl(project).findClass(symbol, scope)
         if (clazz != null) {
             return clazz.methods.map { "${clazz.qualifiedName}#${it.name}" }
         }
 
         // for lookup for method
+        val method = symbol.split("#")
+        if (method.size == 2) {
+            val clazzName = method[0]
+            val methodName = method[1]
+            return lookupWithMethodName(project, clazzName, scope, methodName)
+        }
 
+        // may by not our format, like <package>.<class>.<method> split last
+        val lastDotIndex = symbol.lastIndexOf(".")
+        if (lastDotIndex != -1) {
+            val clazzName = symbol.substring(0, lastDotIndex)
+            val methodName = symbol.substring(lastDotIndex + 1)
+            return lookupWithMethodName(project, clazzName, scope, methodName)
+        }
+
+        return emptyList()
+    }
+
+    private fun lookupWithMethodName(
+        project: Project,
+        clazzName: String,
+        scope: GlobalSearchScope,
+        methodName: String
+    ): List<String> {
+        val psiClass = JavaFileManagerImpl(project).findClass(clazzName, scope)
+        if (psiClass != null) {
+            val psiMethod = psiClass.findMethodsByName(methodName, true).firstOrNull()
+            if (psiMethod != null) {
+                return listOf(psiMethod.text)
+            }
+        }
 
         return emptyList()
     }