Share logic between flow and ts (#14545)

src/language-js/print/flow.js

@@ -22,6 +22,8 @@ import {
   printNamedTupleMember,
   printTypeAnnotation,
   printTypeAnnotationProperty,
+  printArrayType,
+  printTypeQuery,
 } from "./type-annotation.js";
 import { printInterface } from "./interface.js";
 import { printTypeParameter, printTypeParameters } from "./type-parameters.js";
@@ -113,7 +115,7 @@ function printFlow(path, options, print) {
     case "TypeParameter":
       return printTypeParameter(path, options, print);
     case "TypeofTypeAnnotation":
-      return ["typeof ", print("argument")];
+      return printTypeQuery(path, print);
     case "ExistsTypeAnnotation":
       return "*";
     case "EmptyTypeAnnotation":
@@ -121,7 +123,7 @@ function printFlow(path, options, print) {
     case "MixedTypeAnnotation":
       return "mixed";
     case "ArrayTypeAnnotation":
-      return [print("elementType"), "[]"];
+      return printArrayType(print);
     case "BooleanLiteralTypeAnnotation":
       return String(node.value);
 

src/language-js/print/type-annotation.js

@@ -476,6 +476,27 @@ function printTypeAnnotation(path, options, print) {
     : print("typeAnnotation");
 }
 
+/*
+- `TSArrayType`
+- `ArrayTypeAnnotation`
+*/
+function printArrayType(print) {
+  return [print("elementType"), "[]"];
+}
+
+/*
+- `TSTypeQuery`
+- `TypeofTypeAnnotation`
+*/
+function printTypeQuery({ node }, print) {
+  return [
+    "typeof ",
+    ...(node.type === "TSTypeQuery"
+      ? [print("exprName"), print("typeParameters")]
+      : [print("argument")]),
+  ];
+}
+
 export {
   printOpaqueType,
   printTypeAlias,
@@ -489,4 +510,6 @@ export {
   printNamedTupleMember,
   printTypeAnnotationProperty,
   printTypeAnnotation,
+  printArrayType,
+  printTypeQuery,
 };

src/language-js/print/typescript.js

@@ -52,6 +52,8 @@ import {
   printNamedTupleMember,
   printTypeAnnotation,
   printTypeAnnotationProperty,
+  printArrayType,
+  printTypeQuery,
 } from "./type-annotation.js";
 import { printEnumDeclaration, printEnumMember } from "./enum.js";
 
@@ -114,7 +116,7 @@ function printTypescript(path, options, print) {
     case "TSTypeAliasDeclaration":
       return printTypeAlias(path, options, print);
     case "TSQualifiedName":
-      return join(".", [print("left"), print("right")]);
+      return [print("left"), ".", print("right")];
     case "TSAbstractMethodDefinition":
     case "TSDeclareMethod":
       return printClassMethod(path, options, print);
@@ -155,7 +157,7 @@ function printTypescript(path, options, print) {
       return parts;
     }
     case "TSArrayType":
-      return [print("elementType"), "[]"];
+      return printArrayType(print);
     case "TSPropertySignature":
       return [
         node.readonly ? "readonly " : "",
@@ -174,7 +176,7 @@ function printTypescript(path, options, print) {
       ];
 
     case "TSTypeQuery":
-      return ["typeof ", print("exprName"), print("typeParameters")];
+      return printTypeQuery(path, print);
     case "TSIndexSignature": {
       // The typescript parser accepts multiple parameters here. If you're
       // using them, it makes sense to have a trailing comma. But if you
@@ -382,7 +384,7 @@ function printTypescript(path, options, print) {
       return printTernary(path, options, print);
 
     case "TSInferType":
-      return ["infer", " ", print("typeParameter")];
+      return ["infer ", print("typeParameter")];
     case "TSIntersectionType":
       return printIntersectionType(path, options, print);
     case "TSUnionType":