better typing of some globals

compiler/packages/babel-plugin-react-compiler/src/HIR/Environment.ts

@@ -679,7 +679,7 @@ export class Environment {
         );
       }
       case 'ImportSpecifier': {
-        if (this.#isKnownReactModule(binding.module)) {
+        if (this.#isKnownTypedModule(binding.module)) {
           /**
            * For `import {imported as name} from "..."` form, we use the `imported`
            * name rather than the local alias. Because we don't have definitions for
@@ -707,7 +707,7 @@ export class Environment {
       }
       case 'ImportDefault':
       case 'ImportNamespace': {
-        if (this.#isKnownReactModule(binding.module)) {
+        if (this.#isKnownTypedModule(binding.module)) {
           // only resolve imports to modules we know about
           return (
             this.#globals.get(binding.name) ??
@@ -720,10 +720,11 @@ export class Environment {
     }
   }
 
-  #isKnownReactModule(moduleName: string): boolean {
+  #isKnownTypedModule(moduleName: string): boolean {
     return (
       moduleName.toLowerCase() === 'react' ||
       moduleName.toLowerCase() === 'react-dom' ||
+      moduleName.toLowerCase() === 'fbt' ||
       (this.config.enableSharedRuntime__testonly &&
         moduleName === 'shared-runtime')
     );

compiler/packages/babel-plugin-react-compiler/src/HIR/Globals.ts

@@ -83,7 +83,7 @@ const UNTYPED_GLOBALS: Set<string> = new Set([
 const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
   [
     'Array',
-    addObject(DEFAULT_SHAPES, 'Array', [
+    addFunction(DEFAULT_SHAPES, [
       [
         'isArray',
         // Array.isArray(value)
@@ -117,7 +117,12 @@ const TYPED_GLOBALS: Array<[string, BuiltInType]> = [
           returnValueKind: ValueKind.Mutable,
         }),
       ],
-    ]),
+    ], {positionalParams: [],
+      restParam: Effect.Read,
+      returnType: {kind: 'Object', shapeId: BuiltInArrayId},
+      calleeEffect: Effect.Read,
+      returnValueKind: ValueKind.Mutable
+    } , 'Array'),
   ],
   [
     'Math',
@@ -391,6 +396,46 @@ const REACT_APIS: Array<[string, BuiltInType]> = [
   ],
 ];
 
+const FBT_FUNCTION = {
+  positionalParams: [],
+  restParam: Effect.Read,
+  returnType: {kind: 'Primitive'} as const,
+  calleeEffect: Effect.Read,
+  returnValueKind: ValueKind.Primitive,
+}
+
+const FBT_APIS: Array<[string, BuiltInType]> = [
+  [
+    'param',
+    addFunction(DEFAULT_SHAPES, [], FBT_FUNCTION),
+  ],
+  [
+    'enum',
+    addFunction(DEFAULT_SHAPES, [], FBT_FUNCTION),
+  ],
+  [
+    'name',
+    addFunction(DEFAULT_SHAPES, [], FBT_FUNCTION),
+  ],
+  [
+    'plural',
+    addFunction(DEFAULT_SHAPES, [], FBT_FUNCTION),
+  ],
+  [
+    'pronoun',
+    addFunction(DEFAULT_SHAPES, [], FBT_FUNCTION),
+  ],
+  [
+    'isFbtInstance',
+    addFunction(DEFAULT_SHAPES, [], FBT_FUNCTION),
+  ],
+]
+
+TYPED_GLOBALS.push([
+  'fbt',
+  addFunction(DEFAULT_SHAPES, FBT_APIS, FBT_FUNCTION)
+]);
+
 TYPED_GLOBALS.push(
   [
     'React',

compiler/packages/babel-plugin-react-compiler/src/HIR/ObjectShape.ts

@@ -284,6 +284,16 @@ addObject(BUILTIN_SHAPES, BuiltInArrayId, [
       returnValueKind: ValueKind.Primitive,
     }),
   ],
+  [
+    'fill',
+    addFunction(BUILTIN_SHAPES, [], {
+      positionalParams: [],
+      restParam: Effect.Read,
+      returnType: PRIMITIVE_TYPE,
+      calleeEffect: Effect.Store,
+      returnValueKind: ValueKind.Mutable,
+    }),
+  ],
   [
     'slice',
     addFunction(BUILTIN_SHAPES, [], {