add tests for ReturnType and available Arrow as FnParam

tests/cases/fourslash/refactorConvertArrowFunctionOrFunctionExpression_Availability_Arrow_FnParam.ts

@@ -0,0 +1,30 @@
+/// <reference path='fourslash.ts' />
+
+//// function foo(a){}
+//// /*z*/f/*y*/oo/*x*/(/*w*//*v*/(/*u*//*t*/a/*s*/, b) => /*r*/a/*q*/ + b)
+
+
+goTo.select("z", "y");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to named function");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to anonymous function");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to arrow function");
+
+goTo.select("x", "w");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to named function");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to anonymous function");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to arrow function");
+
+goTo.select("v", "u");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to named function");
+verify.refactorAvailable("Convert arrow function or function expression", "Convert to anonymous function");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to arrow function");
+
+goTo.select("t", "s");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to named function");
+verify.refactorAvailable("Convert arrow function or function expression", "Convert to anonymous function");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to arrow function");
+
+goTo.select("r", "q");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to named function");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to anonymous function");
+verify.not.refactorAvailable("Convert arrow function or function expression", "Convert to arrow function");

tests/cases/fourslash/refactorConvertArrowFunctionOrFunctionExpression_ToAnon_RetType.ts

@@ -0,0 +1,13 @@
+/// <reference path='fourslash.ts' />
+
+//// const foo = /*x*/(/*y*/): number => a + 1;
+
+goTo.select("x", "y");
+edit.applyRefactor({
+    refactorName: "Convert arrow function or function expression",
+    actionName: "Convert to anonymous function",
+    actionDescription: "Convert to anonymous function",
+    newContent: `const foo = function(): number {
+    return a + 1;
+};`,
+});

tests/cases/fourslash/refactorConvertArrowFunctionOrFunctionExpression_ToArrow_RetType.ts

@@ -0,0 +1,13 @@
+/// <reference path='fourslash.ts' />
+
+//// const foo = /*x*/f/*y*/unction(): string {
+////    return "foobar";
+//// };
+
+goTo.select("x", "y");
+edit.applyRefactor({
+    refactorName: "Convert arrow function or function expression",
+    actionName: "Convert to arrow function",
+    actionDescription: "Convert to arrow function",
+    newContent: `const foo = (): string => "foobar";`,
+});

tests/cases/fourslash/refactorConvertArrowFunctionOrFunctionExpression_ToNamed_RetType.ts

@@ -0,0 +1,13 @@
+/// <reference path='fourslash.ts' />
+
+//// let foo = /*x*/(/*y*/): number => 42;
+
+goTo.select("x", "y");
+edit.applyRefactor({
+    refactorName: "Convert arrow function or function expression",
+    actionName: "Convert to named function",
+    actionDescription: "Convert to named function",
+    newContent: `function foo(): number {
+    return 42;
+}`,
+});