Bug 570016: Enable type argument completions in lambda blockI20210121-2140I20210120-1800I20210120-1400

Inside lambda block the type argument completion is not working due to
the ParameterizedSingleTypeReference is not resolved. This fix will try
to move the ParameterizedSingleTypeReference expression as a lambda
block statement so that it get resolved when resolving the
CompilationUnit.

Also reverted and adjusted the
https://bugs.eclipse.org/bugs/show_bug.cgi?id=460410

Change-Id: Ib8bbe848675fc961eb69952039e4314ace9e25e2
Signed-off-by: Gayan Perera <gayanper@gmail.com>

3 files changed, 49 insertions, 8 deletions

diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests18.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests18.java
index 6e2444f0b3..f38b48b005 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests18.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/CompletionTests18.java
@@ -2495,7 +2495,7 @@ public void testBug459189_004() throws JavaModelException {
 			requestor.getResults());
 }
 public void testBug460410() throws JavaModelException {
-	this.workingCopies = new ICompilationUnit[1];
+	this.workingCopies = new ICompilationUnit[2];
 	this.workingCopies[0] = getWorkingCopy(
 			"/Completion/src/X.java",
 			"import java.util.ArrayList;\n" +
@@ -2504,9 +2504,16 @@ public void testBug460410() throws JavaModelException {
 			"	public static void main(String[] args) {\n"+
 			"		ArrayList<Supplier<Runnable>> list = new ArrayList<>();\n"+
 			"		list.forEach((supp) -> {\n"+
-			"			Supplier<Run/* HERE */>}\n"+
+			"			Supplier<Bug460/* HERE */>}\n"+
 			"		});\n"+
 			"	}\n"+
+			"	public static class Bug460410 {" +
+			"	}" +
+			"}\n");
+	this.workingCopies[1] = getWorkingCopy(
+			"/Completion/src/Bug460411.java",
+			"package abc;" +
+			"public class Bug460411 {\n"+
 			"}\n");
 
 	CompletionTestsRequestor2 requestor = new CompletionTestsRequestor2(true);
@@ -2515,7 +2522,42 @@ public void testBug460410() throws JavaModelException {
 	String completeBehind = "/* HERE */";
 	int cursorLocation = str.indexOf(completeBehind);
 	this.workingCopies[0].codeComplete(cursorLocation, requestor, this.wcOwner);
-	assertResults("", requestor.getResults());
+	assertResults(
+			"Bug460411[TYPE_REF]{abc.Bug460411, abc, Labc.Bug460411;, null, null, " + (R_DEFAULT + 39) + "}\n" +
+			"Bug460410[TYPE_REF]{Bug460410, , LBug460410;, null, null, " + (R_DEFAULT + 42) + "}",
+			requestor.getResults());
+}
+public void testBug462015() throws JavaModelException {
+	this.workingCopies = new ICompilationUnit[2];
+	this.workingCopies[0] = getWorkingCopy(
+			"/Completion/src/X.java",
+			"package abc;\n" +
+			"import java.util.ArrayList;\n" +
+			"import java.util.stream.Collectors;\n" +
+			"public class X {\n"+
+			"	public static void main(String[] args) {\n"+
+			"		ArrayList<Entry> list = new ArrayList<>();\n"+
+			"		list.stream().collect(Collectors.averagingInt(e -> e.a/* HERE */));\n"+
+			"	}\n"+
+			"}\n");
+	this.workingCopies[1] = getWorkingCopy(
+			"/Completion/src/Entry.java",
+			"package abc;" +
+			"public class Entry {\n"+
+			"	public String age() {\n"+
+			"		return \"10\";"+
+			"	}"+
+			"}\n");
+
+	CompletionTestsRequestor2 requestor = new CompletionTestsRequestor2(true);
+	requestor.allowAllRequiredProposals();
+	String str = this.workingCopies[0].getSource();
+	String completeBehind = "/* HERE */";
+	int cursorLocation = str.indexOf(completeBehind);
+	this.workingCopies[0].codeComplete(cursorLocation, requestor, this.wcOwner);
+	assertResults(
+			"age[METHOD_REF]{age(), LEntry;, ()Ljava.lang.String;, age, null, " + (R_DEFAULT + 30) + "}",
+			requestor.getResults());
 }
 // https://bugs.eclipse.org/bugs/show_bug.cgi?id=481564
 public void testBug481564() throws JavaModelException {
diff --git a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/CompletionEngine.java b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/CompletionEngine.java
index afffe434a9..27e4f01b0e 100644
--- a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/CompletionEngine.java
+++ b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/CompletionEngine.java
@@ -13038,9 +13038,6 @@ public final class CompletionEngine
 
 		if(parent instanceof ParameterizedSingleTypeReference) {
 			ParameterizedSingleTypeReference ref = (ParameterizedSingleTypeReference) parent;
-			if (ref.resolvedType == null) {
-				return false;
-			}
 			TypeVariableBinding[] typeVariables = ((ReferenceBinding)ref.resolvedType).typeVariables();
 			int length = ref.typeArguments == null ? 0 : ref.typeArguments.length;
 			int nodeIndex = -1;
diff --git a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
index ecbcfcb88f..e54d74513d 100644
--- a/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
+++ b/org.eclipse.jdt.core/codeassist/org/eclipse/jdt/internal/codeassist/complete/CompletionParser.java
@@ -2744,8 +2744,10 @@ protected void consumeEmptyStatement() {
 	   we don't know whether it is the first or subsequent statement in a block to be able to
 	   decide whether to call contactNodeLists. See Parser.consumeBlockStatement(s)
 	*/
-	if (this.shouldStackAssistNode && this.assistNode != null)
-		this.astStack[this.astPtr] = this.assistNodeParent instanceof MessageSend ? this.assistNodeParent : this.assistNode;
+	if (this.shouldStackAssistNode && this.assistNode != null) {
+		this.astStack[this.astPtr] = (this.assistNodeParent instanceof MessageSend)
+				|| (this.assistNodeParent instanceof ParameterizedSingleTypeReference) ? this.assistNodeParent : this.assistNode;
+	}
 	this.shouldStackAssistNode = false;
 }
 @Override