Preserve type parameters in function-typed "this." and "super." params.

CHANGELOG.md

@@ -3,6 +3,8 @@
 * Allow passing a language version to `DartFomatter()`. Formatted code will be
   parsed at that version. If omitted, defaults to the latest version. In a
   future release, this parameter will become required.
+* Preserve type parameters on old-style function-typed formals that also use
+  `this.` or `super.` (#1321).
 * Remove temporary work around for analyzer 6.2.0 from dart_style 2.3.6.
 * Require `package:analyzer` `>=6.5.0 <7.0.0`.
 

lib/src/short/source_visitor.dart

@@ -1339,6 +1339,7 @@ class SourceVisitor extends ThrowingAstVisitor {
       token(node.thisKeyword);
       token(node.period);
       token(node.name);
+      visit(node.typeParameters);
       visit(node.parameters);
       token(node.question);
       _endFormalParameter(node);
@@ -2801,6 +2802,7 @@ class SourceVisitor extends ThrowingAstVisitor {
       token(node.superKeyword);
       token(node.period);
       token(node.name);
+      visit(node.typeParameters);
       visit(node.parameters);
       token(node.question);
       _endFormalParameter(node);

test/short/regression/1300/1321.unit

@@ -0,0 +1,38 @@
+>>> `super.` parameter.
+class A {
+  A(int foo<T>(int a));
+}
+class B extends A {
+  B.sub1(int super.bar1<T1>(int a1),);
+  B.sub2(int super.bar2<T2>(int a2),);
+}
+main() {}
+<<<
+class A {
+  A(int foo<T>(int a));
+}
+
+class B extends A {
+  B.sub1(
+    int super.bar1<T1>(int a1),
+  );
+  B.sub2(
+    int super.bar2<T2>(int a2),
+  );
+}
+
+main() {}
+>>> `this.` parameter.
+class A {
+  A.sub1(int this.bar1<T1>(int a1),);
+  A.sub2(int this.bar2<T2>(int a2),);
+}
+<<<
+class A {
+  A.sub1(
+    int this.bar1<T1>(int a1),
+  );
+  A.sub2(
+    int this.bar2<T2>(int a2),
+  );
+}

test/tall/regression/1300/1321.unit

@@ -0,0 +1,30 @@
+>>> `super.` parameter.
+class A {
+  A(int foo<T>(int a));
+}
+class B extends A {
+  B.sub1(int super.bar1<T1>(int a1),);
+  B.sub2(int super.bar2<T2>(int a2),);
+}
+main() {}
+<<<
+class A {
+  A(int foo<T>(int a));
+}
+
+class B extends A {
+  B.sub1(int super.bar1<T1>(int a1));
+  B.sub2(int super.bar2<T2>(int a2));
+}
+
+main() {}
+>>> `this.` parameter.
+class A {
+  A.sub1(int this.bar1<T1>(int a1),);
+  A.sub2(int this.bar2<T2>(int a2),);
+}
+<<<
+class A {
+  A.sub1(int this.bar1<T1>(int a1));
+  A.sub2(int this.bar2<T2>(int a2));
+}