Update JS API snapshot to group exports in single block (#52235)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/52235

Adds `organizeDeclarations` transform, replacing `sortTypeDefinitions`.

All `export declare ...` statements are now collected and represented at the end of the snapshot in a single `export {}` block — significantly improving readability and diffing.

Changelog: [Internal]

Reviewed By: j-piasecki

Differential Revision: D77150017

fbshipit-source-id: 1bd451c0e2a18fd6fc0504970b10a5d2502ac872

scripts/build-types/BuildApiSnapshot.js

@@ -36,10 +36,10 @@ const inputFilesPostTransforms: $ReadOnlyArray<PluginObj<mixed>> = [
 
 const postTransforms: $ReadOnlyArray<PluginObj<mixed>> = [
   require('./transforms/typescript/stripUnstableApis'),
-  require('./transforms/typescript/sortTypeDefinitions'),
   require('./transforms/typescript/sortProperties'),
   require('./transforms/typescript/sortUnions'),
   require('./transforms/removeUndefinedFromOptionalMembers'),
+  require('./transforms/typescript/organizeDeclarations'),
 ];
 
 async function buildAPISnapshot(validate: boolean) {

scripts/build-types/transforms/typescript/__tests__/__snapshots__/organizeDeclarations-test.js.snap

@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`sortTypeDefinitions should divide top-lelvel declarations into exported and non-exported sections 1`] = `
+exports[`organizeDeclarations should sort declarations and move exports into single export block 1`] = `
 "/**
  * Copyright (c) Meta Platforms, Inc. and affiliates.
  *
@@ -9,16 +9,17 @@ exports[`sortTypeDefinitions should divide top-lelvel declarations into exported
  */
 
 import * as React from \\"react\\";
-export declare type ExportedFoo = \\"A\\" | \\"B\\";
-export declare type ExportedBar = null | string | number;
-export declare class ExportedBaz {
-  foo: string;
-}
-export declare function exportedFn(): void;
-declare type Foo = \\"A\\" | \\"B\\";
 declare type Bar = null | string | number;
 declare class Baz {
   foo: string;
 }
-declare function fn(): void;"
+declare type ExportedBar = null | string | number;
+declare class ExportedBaz {
+  foo: string;
+}
+declare function exportedFn(): void;
+declare type ExportedFoo = \\"A\\" | \\"B\\";
+declare function fn(): void;
+declare type Foo = \\"A\\" | \\"B\\";
+export { ExportedBar, ExportedBaz, ExportedFoo, exportedFn };"
 `;

scripts/build-types/transforms/typescript/__tests__/organizeDeclarations-test.js

@@ -8,23 +8,23 @@
  * @format
  */
 
-const sortTypeDefinitionsVisitor = require('../sortTypeDefinitions');
+const organizeDeclarations = require('../organizeDeclarations');
 const babel = require('@babel/core');
 const {promises: fs} = require('fs');
 const path = require('path');
 
 async function translate(code: string): Promise<string> {
   const result = await babel.transformAsync(code, {
-    plugins: ['@babel/plugin-syntax-typescript', sortTypeDefinitionsVisitor],
+    plugins: ['@babel/plugin-syntax-typescript', organizeDeclarations],
   });
 
   return result.code;
 }
 
-describe('sortTypeDefinitions', () => {
-  test('should divide top-lelvel declarations into exported and non-exported sections', async () => {
+describe('organizeDeclarations', () => {
+  test('should sort declarations and move exports into single export block', async () => {
     const code = await fs.readFile(
-      path.join(__dirname, '../__fixtures__/sortTypeDefinitions.d.ts'),
+      path.join(__dirname, '../__fixtures__/organizeDeclarations.d.ts'),
       'utf-8',
     );
     const result = await translate(code);

scripts/build-types/transforms/typescript/organizeDeclarations.js

@@ -0,0 +1,94 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+import type {PluginObj} from '@babel/core';
+
+import * as t from '@babel/types';
+
+/**
+ * A visitor that organizes top level type declarations into our desired API
+ * snapshot format.
+ *
+ * - Sorts declarations alphabetically.
+ * - Moves all exports into a single block at the end of the file.
+ */
+const visitor: PluginObj<mixed> = {
+  visitor: {
+    Program(path) {
+      const exportedIdentifiers: Set<string> = new Set();
+
+      // Collect exported identifiers
+      path.get('body').forEach(nodePath => {
+        if (nodePath.isExportNamedDeclaration()) {
+          if (nodePath.node.declaration) {
+            const declaration = nodePath.node.declaration;
+            if (
+              t.isTSInterfaceDeclaration(declaration) ||
+              t.isTSTypeAliasDeclaration(declaration) ||
+              t.isFunctionDeclaration(declaration) ||
+              t.isClassDeclaration(declaration) ||
+              t.isVariableDeclaration(declaration) ||
+              t.isTSDeclareFunction(declaration) ||
+              t.isTSModuleDeclaration(declaration) ||
+              t.isTSEnumDeclaration(declaration)
+            ) {
+              if (declaration.id && declaration.id.name != null) {
+                exportedIdentifiers.add(declaration.id.name);
+              } else if (
+                t.isVariableDeclaration(declaration) &&
+                declaration.declarations.length > 0
+              ) {
+                declaration.declarations.forEach(declarator => {
+                  if (t.isIdentifier(declarator.id)) {
+                    exportedIdentifiers.add(declarator.id.name);
+                  }
+                });
+              }
+              nodePath.replaceWith(declaration); // Remove export
+            } else {
+              throw new Error(
+                `Unexpected declaration type for top-level export: ${declaration.type}`,
+              );
+            }
+          } else if (nodePath.node.specifiers) {
+            nodePath.node.specifiers.forEach(specifier => {
+              if (specifier.type === 'ExportSpecifier') {
+                exportedIdentifiers.add(specifier.local.name);
+              }
+            });
+            nodePath.remove(); // Remove export statement
+          }
+        }
+      });
+
+      // Sort declarations alphabetically
+      path.node.body.sort((a, b) => {
+        const aName = a.id?.name || '';
+        const bName = b.id?.name || '';
+        return aName.localeCompare(bName);
+      });
+
+      // Move all exports into single `export {}` block
+      if (exportedIdentifiers.size > 0) {
+        const sortedIdentifiers = Array.from(exportedIdentifiers).sort();
+        const exportStatement = t.exportNamedDeclaration(
+          // $FlowIgnore[incompatible-call]
+          null,
+          sortedIdentifiers.map(name =>
+            t.exportSpecifier(t.identifier(name), t.identifier(name)),
+          ),
+        );
+        path.pushContainer('body', exportStatement);
+      }
+    },
+  },
+};
+
+module.exports = visitor;

scripts/build-types/transforms/typescript/sortTypeDefinitions.js

@@ -1,42 +0,0 @@
-/**
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @flow strict-local
- * @format
- */
-
-import type {PluginObj} from '@babel/core';
-
-import * as t from '@babel/types';
-
-const visitor: PluginObj<mixed> = {
-  visitor: {
-    Program(path) {
-      path.node.body.sort((a, b) => {
-        // Push import declarations at the top of the file
-        if (t.isImportDeclaration(a) && !t.isImportDeclaration(b)) {
-          return -1;
-        } else if (!t.isImportDeclaration(a) && t.isImportDeclaration(b)) {
-          return 1;
-        }
-
-        const aExported = t.isExportNamedDeclaration(a);
-        const bExported = t.isExportNamedDeclaration(b);
-
-        // Push exported declarations before non-exported declarations
-        if (aExported && !bExported) {
-          return -1;
-        } else if (!aExported && bExported) {
-          return 1;
-        }
-
-        return 0;
-      });
-    },
-  },
-};
-
-module.exports = visitor;