GH-52 fix groovy folding arg list

src/main/kotlin/com/akefirad/groom/groovy/GroovyFoldingBuilder.kt

@@ -8,8 +8,6 @@ import com.intellij.lang.folding.FoldingDescriptor
 import com.intellij.openapi.editor.Document
 import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiElement
-import com.intellij.psi.tree.TokenSet
-import org.jetbrains.plugins.groovy.lang.parser.GroovyElementTypes
 import org.jetbrains.plugins.groovy.lang.psi.GroovyFile
 import org.jetbrains.plugins.groovy.lang.psi.api.auxiliary.GrListOrMap
 
@@ -39,20 +37,17 @@ class GroovyFoldingBuilder : CustomFoldingBuilder() {
             val start = child.startOffset
             val end = child.endOffset
             val range = TextRange(start, end)
-            d.add(FoldingDescriptor(e.node, range))
+            d.add(FoldingDescriptor(child.node, range))
         }
     }
 
     private fun GrListOrMap.hasNoChildren() = children.isEmpty()
     private fun GrListOrMap.isSingleLine() = !text.contains("\n") // TODO: find a better way to do these!
     private fun GrListOrMap.hasLeftOpen() = !text.trim().endsWith("]") // TODO: find a better way to do these!
 
-    public override fun getLanguagePlaceholderText(node: ASTNode, range: TextRange): String {
-        val selected = node.getChildren(TokenSet.create(GroovyElementTypes.LIST_OR_MAP))
-        assert(selected.size == 1) { "Unexpected number of children: ${selected.size}" }
-        val psi = selected.single().psi
-        check(psi is GrListOrMap) { "Unexpected type: ${psi.javaClass}" }
-        return if (psi.isMap) "[...:...]" else "[...]"
+    public override fun getLanguagePlaceholderText(node: ASTNode, range: TextRange) = node.psi.let {
+        check(it is GrListOrMap) { "Unexpected type: ${it.javaClass}" }
+        if (it.isMap) "[...:...]" else "[...]"
     }
 
     override fun isRegionCollapsedByDefault(node: ASTNode) = false

src/test/groovy/com/akefirad/groom/groovy/GroovyFoldingBuilderTest.groovy

@@ -9,12 +9,10 @@ import com.intellij.testFramework.fixtures.LightPlatformCodeInsightFixture4TestC
 import org.junit.Test
 
 import static com.akefirad.oss.easymock.EasyMock.mock
-import static org.easymock.EasyMock.anyObject
 import static org.easymock.EasyMock.expect
 import static org.easymock.EasyMock.replay
 import static org.easymock.EasyMock.verify
 
-
 class GroovyFoldingBuilderTest extends LightPlatformCodeInsightFixture4TestCase {
 
     @Override
@@ -46,34 +44,17 @@ class GroovyFoldingBuilderTest extends LightPlatformCodeInsightFixture4TestCase
     }
 
     @Test
-    void 'getLanguagePlaceholderText should fail when node has no list or map'() {
+    void 'getLanguagePlaceholderText should fail when node is not GrListOrMap'() {
         // given:
         def subject = new GroovyFoldingBuilder()
         def node = mock(ASTNode)
-        expect(node.getChildren(anyObject())).andReturn(new ASTNode[0])
+        expect(node.getPsi()).andReturn(mock(PsiElement))
         replay(node)
 
         // expect:
-        assertThrows(AssertionError) { subject.getLanguagePlaceholderText(node, new TextRange(0, 0)) }
+        assertThrows(IllegalStateException) { subject.getLanguagePlaceholderText(node, TextRange.EMPTY_RANGE) }
 
         // and:
         verify(node)
     }
-
-    @Test
-    void 'getLanguagePlaceholderText should fail when node has non-list-map child'() {
-        // given:
-        def subject = new GroovyFoldingBuilder()
-        def node = mock(ASTNode)
-        def child = mock(ASTNode)
-        expect(child.psi).andReturn(mock(PsiElement))
-        expect(node.getChildren(anyObject())).andReturn(new ASTNode[]{child})
-        replay(node, child)
-
-        // expect:
-        assertThrows(IllegalStateException) { subject.getLanguagePlaceholderText(node, new TextRange(0, 0)) }
-
-        // and:
-        verify(node, child)
-    }
 }

src/test/resources/test-data/GroovyFoldingBuilderTest/ExpectedTestData.groovy

@@ -12,6 +12,9 @@ class SampleClass extends Specification <fold text='{...}'>{
 
             println([])
             println([ ])
+
+            println([], [])
+            println([ ], [ ])
     }</fold>
 
     def 'empty map should fold'() <fold text='{...}'>{
@@ -23,6 +26,9 @@ class SampleClass extends Specification <fold text='{...}'>{
 
             println([:])
             println([ : ])
+
+            println([:], [:])
+            println([ : ], [ : ])
     }</fold>
 
     def 'non-empty list should fold'() <fold text='{...}'>{
@@ -37,6 +43,15 @@ class SampleClass extends Specification <fold text='{...}'>{
                 1,
                 2,
             ]</fold>)
+
+            println([1, 2], [3, 4])
+            println(<fold text='[...]'>[
+                1,
+                2,
+            ]</fold>, <fold text='[...]'>[
+                1,
+                2,
+            ]</fold>)
      }</fold>
 
     def 'non-empty map should fold'() <fold text='{...}'>{
@@ -51,6 +66,15 @@ class SampleClass extends Specification <fold text='{...}'>{
                 foo: 1,
                 bar: 2,
             ]</fold>)
+
+            println([foo: 1, bar: 2], [baz: 3, qux: 4])
+            println(<fold text='[...:...]'>[
+                foo: 1,
+                bar: 2,
+            ]</fold>, <fold text='[...:...]'>[
+                foo: 1,
+                bar: 2,
+            ]</fold>)
      }</fold>
 
    def 'nexted list/map should not fold'() <fold text='{...}'>{