fixAddMissingMember: Add a new PropertyDeclaration at the end of the first set (#23837)

src/services/codefixes/fixAddMissingMember.ts

@@ -132,7 +132,24 @@ namespace ts.codefix {
             /*questionToken*/ undefined,
             typeNode,
             /*initializer*/ undefined);
-        changeTracker.insertNodeAtClassStart(classDeclarationSourceFile, classDeclaration, property);
+
+        const lastProp = getNodeToInsertPropertyAfter(classDeclaration);
+        if (lastProp) {
+            changeTracker.insertNodeAfter(classDeclarationSourceFile, lastProp, property);
+        }
+        else {
+            changeTracker.insertNodeAtClassStart(classDeclarationSourceFile, classDeclaration, property);
+        }
+    }
+
+    // Gets the last of the first run of PropertyDeclarations, or undefined if the class does not start with a PropertyDeclaration.
+    function getNodeToInsertPropertyAfter(cls: ClassLikeDeclaration): PropertyDeclaration | undefined {
+        let res: PropertyDeclaration | undefined;
+        for (const member of cls.members) {
+            if (!isPropertyDeclaration(member)) break;
+            res = member;
+        }
+        return res;
     }
 
     function createAddIndexSignatureAction(context: CodeFixContext, classDeclarationSourceFile: SourceFile, classDeclaration: ClassLikeDeclaration, tokenName: string, typeNode: TypeNode): CodeFixAction {

tests/cases/fourslash/codeFixUndeclaredInStaticMethod.ts

@@ -78,9 +78,8 @@ verify.codeFix({
     index: 1, // fix at index 0 is to change the spelling to 'prop1'
     newFileContent:
 `class A {
-    static prop2: string;
-
     static prop1: number;
+    static prop2: string;
 
     static m2(arg0: any, arg1: any): any {
         throw new Error("Method not implemented.");

tests/cases/fourslash/codeFixUndeclaredPropertyFunctionNonEmptyClass.ts

@@ -11,8 +11,8 @@
 
 verify.rangeAfterCodeFix(`
 class A {
-    x: (x: number, y?: A) => number | A;
     y: number;
+    x: (x: number, y?: A) => number | A;
     constructor(public a: number) {
         this.x = function(x: number, y?: A){
             return x > 0 ? x : y;