Phase 4: add structure, folding, and references

src/test/kotlin/dev/hgh/jai/editor/JaiFoldingBuilderTest.kt

@@ -0,0 +1,65 @@
+package dev.hgh.jai.editor
+
+import com.intellij.testFramework.fixtures.BasePlatformTestCase
+import dev.hgh.jai.lexer.JaiTokenTypes
+
+class JaiFoldingBuilderTest : BasePlatformTestCase() {
+    fun testFoldsMultilineBlocksAndComments() {
+        val text =
+            """
+            main :: () {
+                value := 1;
+            }
+
+            /* a comment
+             * with two lines
+             */
+            """.trimIndent()
+        val file = myFixture.configureByText("folding.jai", text)
+
+        val descriptors = JaiFoldingBuilder().buildFoldRegions(file, myFixture.editor.document, quick = false)
+        val foldedText =
+            descriptors.map { descriptor ->
+                text.substring(descriptor.range.startOffset, descriptor.range.endOffset)
+            }
+
+        assertEquals(2, descriptors.size)
+        assertTrue(foldedText.any { it.contains("value := 1;") })
+        assertTrue(foldedText.any { it.contains("with two lines") })
+    }
+
+    fun testFoldsNestedCommentsAndHereStrings() {
+        val text =
+            """
+            /* outer comment
+               /* nested comment */
+               still in the outer comment
+            */
+            body :: #string END
+            raw here-string text
+            END;
+            """.trimIndent()
+        val file = myFixture.configureByText("literals.jai", text)
+        val builder = JaiFoldingBuilder()
+        val descriptors = builder.buildFoldRegions(file, myFixture.editor.document, quick = false)
+        val foldedText =
+            descriptors.map { descriptor ->
+                text.substring(descriptor.range.startOffset, descriptor.range.endOffset)
+            }
+
+        assertEquals(2, descriptors.size)
+        assertTrue(foldedText.any { it.contains("nested comment") })
+        assertTrue(foldedText.any { it.contains("raw here-string text") })
+        val hereString = descriptors.first { it.element.elementType == JaiTokenTypes.HERE_STRING }
+        assertEquals("#string …", builder.getPlaceholderText(hereString.element))
+    }
+
+    fun testDoesNotFoldSingleLineRegions() {
+        val text = "main :: () { value := 1; } /* one line */"
+        val file = myFixture.configureByText("single-line.jai", text)
+
+        val descriptors = JaiFoldingBuilder().buildFoldRegions(file, myFixture.editor.document, quick = false)
+
+        assertEmpty(descriptors.toList())
+    }
+}