Phase 5: add rename and find usages

src/test/kotlin/dev/hgh/jai/findusages/JaiFindUsagesTest.kt

@@ -0,0 +1,37 @@
+package dev.hgh.jai.findusages
+
+import com.intellij.psi.search.searches.ReferencesSearch
+import com.intellij.psi.util.PsiTreeUtil
+import com.intellij.testFramework.fixtures.BasePlatformTestCase
+import dev.hgh.jai.psi.JaiDeclName
+
+class JaiFindUsagesTest : BasePlatformTestCase() {
+    fun testFindUsagesActionFindsProcedureReference() {
+        val usages = myFixture.testFindUsages("Declaration.jai", "Usage.jai")
+
+        assertEquals(1, usages.size)
+    }
+
+    fun testFindsProcedureReferencesFromDeclaration() {
+        val source =
+            myFixture.addFileToProject(
+                "find-usages.jai",
+                """
+                helper :: () {}
+                first :: () { helper(); }
+                second :: () { helper(); }
+                """.trimIndent(),
+            )
+        val declaration =
+            PsiTreeUtil
+                .findChildrenOfType(source, JaiDeclName::class.java)
+                .single { it.text == "helper" }
+
+        val usages = ReferencesSearch.search(declaration).findAll()
+
+        assertEquals(2, usages.size)
+        assertTrue(usages.all { it.element.text == "helper" })
+    }
+
+    override fun getTestDataPath(): String = "src/test/testData/findusages"
+}