extractMethod: Don't try to extract a single token (#18090)

* extractMethod: Don't try to extract a single token

* Update tests

Author: Andy

src/services/refactors/extractMethod.ts

@@ -92,7 +92,7 @@ namespace ts.refactor.extractMethod {
         export const CannotExtractRangeThatContainsWritesToReferencesLocatedOutsideOfTheTargetRangeInGenerators: DiagnosticMessage = createMessage("Cannot extract range containing writes to references located outside of the target range in generators.");
         export const TypeWillNotBeVisibleInTheNewScope = createMessage("Type will not visible in the new scope.");
         export const FunctionWillNotBeVisibleInTheNewScope = createMessage("Function will not visible in the new scope.");
-        export const InsufficientSelection = createMessage("Select more than a single identifier.");
+        export const InsufficientSelection = createMessage("Select more than a single token.");
         export const CannotExtractExportedEntity = createMessage("Cannot extract exported declaration");
         export const CannotCombineWritesAndReturns = createMessage("Cannot combine writes and returns");
         export const CannotExtractReadonlyPropertyInitializerOutsideConstructor = createMessage("Cannot move initialization of read-only class property outside of the constructor");
@@ -227,7 +227,7 @@ namespace ts.refactor.extractMethod {
         }
 
         function checkRootNode(node: Node): Diagnostic[] | undefined {
-            if (isIdentifier(node)) {
+            if (isToken(node)) {
                 return [createDiagnosticForNode(node, Messages.InsufficientSelection)];
             }
             return undefined;

tests/cases/fourslash/extract-method-not-for-token.ts

@@ -0,0 +1,6 @@
+/// <reference path='fourslash.ts' />
+
+////"/**/foo";
+
+goTo.marker("");
+verify.not.refactorAvailable('Extract Method');

tests/cases/fourslash/extract-method13.ts

@@ -4,8 +4,8 @@
 // Also checks that we correctly find non-conflicting names in static contexts.
 
 //// class C {
-////     static j = /*c*/100/*d*/;
-////     constructor(q: string = /*a*/"hello"/*b*/) {
+////     static j = /*c*/1 + 1/*d*/;
+////     constructor(q: string = /*a*/"a" + "b"/*b*/) {
 ////     }
 //// }
 
@@ -16,12 +16,12 @@ edit.applyRefactor({
     actionDescription: "Extract function into class 'C'",
     newContent:
 `class C {
-    static j = 100;
+    static j = 1 + 1;
     constructor(q: string = C./*RENAME*/newFunction()) {
     }
 
     private static newFunction(): string {
-        return "hello";
+        return "a" + "b";
     }
 }`
 });
@@ -38,11 +38,11 @@ edit.applyRefactor({
     }
 
     private static newFunction(): string {
-        return "hello";
+        return "a" + "b";
     }
 
     private static newFunction_1() {
-        return 100;
+        return 1 + 1;
     }
 }`
 });

tests/cases/fourslash/extract-method5.ts

@@ -3,7 +3,7 @@
 // You cannot extract a function initializer into the function's body.
 // The innermost scope (scope_0) is the sibling of the function, not the function itself.
 
-//// function fn(x = /*a*/3/*b*/) {
+//// function fn(x = /*a*/1 + 1/*b*/) {
 //// }
 
 goTo.select('a', 'b');
@@ -15,7 +15,7 @@ edit.applyRefactor({
 `function fn(x = /*RENAME*/newFunction()) {
 }
 function newFunction() {
-    return 3;
+    return 1 + 1;
 }
 `
 });