From b56723b5af9b6c5fc52f038c8723d21b03331517 Mon Sep 17 00:00:00 2001
From: lizschwab <liz.schwab@raspberrypi.org>
Date: Thu, 12 Nov 2026 09:54:43 -0800
Subject: [PATCH 1/5] feat: Updated field-date to ESM

---
 eslint.config.mjs                               |  1 +
 packages/plugins/field-date/package.json        | 17 ++++++++++++++---
 packages/plugins/field-date/src/field_date.ts   |  2 +-
 packages/plugins/field-date/src/index.ts        |  2 +-
 .../field-date/test/field_date_test.mocha.js    |  4 ++--
 packages/plugins/field-date/test/index.ts       |  2 +-
 packages/plugins/field-date/tsconfig.json       | 10 ++--------
 7 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/eslint.config.mjs b/eslint.config.mjs
index 84e32d76f49..a51a3be7a6a 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -420,6 +420,7 @@ export default defineConfig(
       'packages/plugins/dev-tools/**',
       'packages/plugins/field-colour/**',
       'packages/plugins/field-colour-hsv-sliders/**',
+      'packages/plugins/field-date/**',
       'packages/plugins/field-grid-dropdown/**',
       'packages/plugins/modal/**',
       'packages/plugins/theme-modern/**',
diff --git a/packages/plugins/field-date/package.json b/packages/plugins/field-date/package.json
index 54687bea681..bd022234af1 100644
--- a/packages/plugins/field-date/package.json
+++ b/packages/plugins/field-date/package.json
@@ -11,9 +11,13 @@
     "start": "blockly-scripts start",
     "test": "blockly-scripts test"
   },
-  "main": "./dist/index.js",
-  "types": "./dist/index.d.ts",
-  "unpkg": "./dist/index.js",
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/esm/index.js",
+  "unpkg": "./dist/esm/index.js",
+  "type": "module",
+  "engines": {
+    "node": ">=24"
+  },
   "author": "Blockly Team",
   "keywords": [
     "blockly",
@@ -41,6 +45,13 @@
     "dist",
     "src"
   ],
+  "exports": {
+    ".": {
+      "node":    {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"},
+      "import":  {"types": "./dist/esm/index.d.ts", "default": "./dist/esm/index.js"},
+      "require": {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"}
+    }
+  },
   "devDependencies": {
     "@blockly/dev-scripts": "^13.4.0",
     "@blockly/dev-tools": "^13.4.0",
diff --git a/packages/plugins/field-date/src/field_date.ts b/packages/plugins/field-date/src/field_date.ts
index cf9601b30f6..47c4bac8553 100644
--- a/packages/plugins/field-date/src/field_date.ts
+++ b/packages/plugins/field-date/src/field_date.ts
@@ -8,7 +8,7 @@
  * @fileoverview Plugin overview.
  */
 import * as Blockly from 'blockly/core';
-import {getLocaleDateString} from './utils';
+import {getLocaleDateString} from './utils.js';
 
 /**
  * Class for a date input field.
diff --git a/packages/plugins/field-date/src/index.ts b/packages/plugins/field-date/src/index.ts
index 480c3fe80de..7b73d409284 100644
--- a/packages/plugins/field-date/src/index.ts
+++ b/packages/plugins/field-date/src/index.ts
@@ -4,4 +4,4 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-export * from './field_date';
+export * from './field_date.js';
diff --git a/packages/plugins/field-date/test/field_date_test.mocha.js b/packages/plugins/field-date/test/field_date_test.mocha.js
index f818c08ce80..204c80b3db9 100644
--- a/packages/plugins/field-date/test/field_date_test.mocha.js
+++ b/packages/plugins/field-date/test/field_date_test.mocha.js
@@ -6,8 +6,8 @@
 
 import {assert} from 'chai';
 import {testHelpers} from '@blockly/dev-tools';
-import {FieldDate} from '../src/index';
-import {getLocaleDateString} from '../src/utils';
+import {FieldDate} from '../src/index.js';
+import {getLocaleDateString} from '../src/utils.js';
 
 const {
   assertFieldValue,
diff --git a/packages/plugins/field-date/test/index.ts b/packages/plugins/field-date/test/index.ts
index 050763dab19..f991a61217e 100644
--- a/packages/plugins/field-date/test/index.ts
+++ b/packages/plugins/field-date/test/index.ts
@@ -10,7 +10,7 @@
 
 import * as Blockly from 'blockly';
 import {createPlayground} from '@blockly/dev-tools';
-import '../src/index';
+import '../src/index.js';
 
 /**
  * An array of blocks that are defined only for the purposes of
diff --git a/packages/plugins/field-date/tsconfig.json b/packages/plugins/field-date/tsconfig.json
index 99858c525f1..a6e04369c08 100644
--- a/packages/plugins/field-date/tsconfig.json
+++ b/packages/plugins/field-date/tsconfig.json
@@ -1,14 +1,8 @@
 {
+  "extends": "@blockly/dev-scripts/config/tsconfig.base.json",
   "compilerOptions": {
     "rootDir": "./src",
-    "outDir": "dist",
-    "declaration": true,
-    "declarationMap": true,
-    "sourceMap": true,
-    "module": "es2015",
-    "moduleResolution": "bundler",
-    "target": "es6",
-    "strict": true
+    "outDir": "dist/esm"
   },
   // NOTE: `test/**/*` is automatically included in `blockly-scripts start`.
   // Only src matters for production builds.

From eeb3c6e241b16d509542d963ba7f74e10a8a77ac Mon Sep 17 00:00:00 2001
From: lizschwab <liz.schwab@raspberrypi.org>
Date: Thu, 12 Nov 2026 10:39:22 -0800
Subject: [PATCH 2/5] feat: Update field-dependent-dropdown to ESM

---
 eslint.config.mjs                               |  1 +
 .../field-dependent-dropdown/package.json       | 17 ++++++++++++++---
 .../src/dependent_dropdown_options_change.ts    |  2 +-
 .../src/field_dependent_dropdown.ts             |  2 +-
 .../field-dependent-dropdown/src/index.ts       |  2 +-
 .../test/field_dependent_dropdown.mocha.js      | 10 ++++------
 .../test/field_dependent_dropdown_test_block.ts |  2 +-
 .../field-dependent-dropdown/test/index.ts      |  2 +-
 .../field-dependent-dropdown/tsconfig.json      | 10 ++--------
 9 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/eslint.config.mjs b/eslint.config.mjs
index a51a3be7a6a..90d9854e4c8 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -421,6 +421,7 @@ export default defineConfig(
       'packages/plugins/field-colour/**',
       'packages/plugins/field-colour-hsv-sliders/**',
       'packages/plugins/field-date/**',
+      'packages/plugins/field-dependent-dropdown/**',
       'packages/plugins/field-grid-dropdown/**',
       'packages/plugins/modal/**',
       'packages/plugins/theme-modern/**',
diff --git a/packages/plugins/field-dependent-dropdown/package.json b/packages/plugins/field-dependent-dropdown/package.json
index 1852efcc3ee..ae03f10d1e4 100644
--- a/packages/plugins/field-dependent-dropdown/package.json
+++ b/packages/plugins/field-dependent-dropdown/package.json
@@ -11,9 +11,13 @@
     "start": "blockly-scripts start",
     "test": "blockly-scripts test"
   },
-  "main": "./dist/index.js",
-  "types": "./dist/index.d.ts",
-  "unpkg": "./dist/index.js",
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/esm/index.js",
+  "unpkg": "./dist/esm/index.js",
+  "type": "module",
+  "engines": {
+    "node": ">=24"
+  },
   "author": "Blockly Team",
   "keywords": [
     "blockly",
@@ -40,6 +44,13 @@
     "dist",
     "src"
   ],
+  "exports": {
+    ".": {
+      "node":    {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"},
+      "import":  {"types": "./dist/esm/index.d.ts", "default": "./dist/esm/index.js"},
+      "require": {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"}
+    }
+  },
   "devDependencies": {
     "@blockly/dev-scripts": "^13.4.0",
     "@blockly/dev-tools": "^13.4.0",
diff --git a/packages/plugins/field-dependent-dropdown/src/dependent_dropdown_options_change.ts b/packages/plugins/field-dependent-dropdown/src/dependent_dropdown_options_change.ts
index ec8efd5ed39..23d6675e081 100644
--- a/packages/plugins/field-dependent-dropdown/src/dependent_dropdown_options_change.ts
+++ b/packages/plugins/field-dependent-dropdown/src/dependent_dropdown_options_change.ts
@@ -10,7 +10,7 @@
  */
 
 import * as Blockly from 'blockly/core';
-import type {FieldDependentDropdown} from './field_dependent_dropdown';
+import type {FieldDependentDropdown} from './field_dependent_dropdown.js';
 
 /**
  * A deep equality comparison between the two provided arrays recursively
diff --git a/packages/plugins/field-dependent-dropdown/src/field_dependent_dropdown.ts b/packages/plugins/field-dependent-dropdown/src/field_dependent_dropdown.ts
index e2348bcd4d6..f451700a27f 100644
--- a/packages/plugins/field-dependent-dropdown/src/field_dependent_dropdown.ts
+++ b/packages/plugins/field-dependent-dropdown/src/field_dependent_dropdown.ts
@@ -10,7 +10,7 @@
  */
 
 import * as Blockly from 'blockly/core';
-import {DependentDropdownOptionsChange} from './dependent_dropdown_options_change';
+import {DependentDropdownOptionsChange} from './dependent_dropdown_options_change.js';
 
 /** The type of the mapping from parent value to child options. */
 export interface ChildOptionMapping {
diff --git a/packages/plugins/field-dependent-dropdown/src/index.ts b/packages/plugins/field-dependent-dropdown/src/index.ts
index e837ff51ff9..5ec13b33f72 100644
--- a/packages/plugins/field-dependent-dropdown/src/index.ts
+++ b/packages/plugins/field-dependent-dropdown/src/index.ts
@@ -4,4 +4,4 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-export * from './field_dependent_dropdown';
+export * from './field_dependent_dropdown.js';
diff --git a/packages/plugins/field-dependent-dropdown/test/field_dependent_dropdown.mocha.js b/packages/plugins/field-dependent-dropdown/test/field_dependent_dropdown.mocha.js
index 61d32499a69..f0f5e268e58 100644
--- a/packages/plugins/field-dependent-dropdown/test/field_dependent_dropdown.mocha.js
+++ b/packages/plugins/field-dependent-dropdown/test/field_dependent_dropdown.mocha.js
@@ -4,12 +4,10 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-const chai = require('chai');
-const sinon = require('sinon');
-const Blockly = require('blockly');
-require('./field_dependent_dropdown_test_block');
-
-const assert = chai.assert;
+import {assert} from 'chai';
+import sinon from 'sinon';
+import * as Blockly from 'blockly';
+import './field_dependent_dropdown_test_block.js';
 
 suite('fieldDependentDropdown', function () {
   setup(function () {
diff --git a/packages/plugins/field-dependent-dropdown/test/field_dependent_dropdown_test_block.ts b/packages/plugins/field-dependent-dropdown/test/field_dependent_dropdown_test_block.ts
index 2cf7c180490..64b86788f52 100644
--- a/packages/plugins/field-dependent-dropdown/test/field_dependent_dropdown_test_block.ts
+++ b/packages/plugins/field-dependent-dropdown/test/field_dependent_dropdown_test_block.ts
@@ -1,5 +1,5 @@
 import * as Blockly from 'blockly';
-import {ChildOptionMapping, FieldDependentDropdown} from '../src/index';
+import {ChildOptionMapping, FieldDependentDropdown} from '../src/index.js';
 
 Blockly.defineBlocksWithJsonArray([
   {
diff --git a/packages/plugins/field-dependent-dropdown/test/index.ts b/packages/plugins/field-dependent-dropdown/test/index.ts
index c69b2e98ce3..1fdea7127be 100644
--- a/packages/plugins/field-dependent-dropdown/test/index.ts
+++ b/packages/plugins/field-dependent-dropdown/test/index.ts
@@ -10,7 +10,7 @@
 
 import * as Blockly from 'blockly';
 import {createPlayground} from '@blockly/dev-tools';
-import './field_dependent_dropdown_test_block';
+import './field_dependent_dropdown_test_block.js';
 
 const toolbox: Blockly.utils.toolbox.ToolboxDefinition = {
   kind: 'flyoutToolbox',
diff --git a/packages/plugins/field-dependent-dropdown/tsconfig.json b/packages/plugins/field-dependent-dropdown/tsconfig.json
index 99858c525f1..a6e04369c08 100644
--- a/packages/plugins/field-dependent-dropdown/tsconfig.json
+++ b/packages/plugins/field-dependent-dropdown/tsconfig.json
@@ -1,14 +1,8 @@
 {
+  "extends": "@blockly/dev-scripts/config/tsconfig.base.json",
   "compilerOptions": {
     "rootDir": "./src",
-    "outDir": "dist",
-    "declaration": true,
-    "declarationMap": true,
-    "sourceMap": true,
-    "module": "es2015",
-    "moduleResolution": "bundler",
-    "target": "es6",
-    "strict": true
+    "outDir": "dist/esm"
   },
   // NOTE: `test/**/*` is automatically included in `blockly-scripts start`.
   // Only src matters for production builds.

From a307ebb3d078647a101285ea3f3024a4e5cef5ae Mon Sep 17 00:00:00 2001
From: lizschwab <liz.schwab@raspberrypi.org>
Date: Thu, 12 Nov 2026 11:38:08 -0800
Subject: [PATCH 3/5] feat: Update field-multilineinput to ESM

---
 eslint.config.mjs                               |  1 +
 .../plugins/field-multilineinput/package.json   | 17 ++++++++++++++---
 .../src/blocks/textMultiline.ts                 |  4 ++--
 .../plugins/field-multilineinput/src/index.ts   |  6 +++---
 .../test/block_test.mocha.js                    |  2 +-
 .../test/field_multilineinput_test.mocha.js     | 15 ++++++++-------
 .../plugins/field-multilineinput/test/index.ts  |  2 +-
 .../plugins/field-multilineinput/tsconfig.json  | 10 ++--------
 8 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/eslint.config.mjs b/eslint.config.mjs
index 90d9854e4c8..687519845d3 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -423,6 +423,7 @@ export default defineConfig(
       'packages/plugins/field-date/**',
       'packages/plugins/field-dependent-dropdown/**',
       'packages/plugins/field-grid-dropdown/**',
+      'packages/plugins/field-multilineinput/**',
       'packages/plugins/modal/**',
       'packages/plugins/theme-modern/**',
       'packages/plugins/typed-variable-modal/**',
diff --git a/packages/plugins/field-multilineinput/package.json b/packages/plugins/field-multilineinput/package.json
index 1b34e957467..1e54a07bf14 100644
--- a/packages/plugins/field-multilineinput/package.json
+++ b/packages/plugins/field-multilineinput/package.json
@@ -12,9 +12,13 @@
     "start": "blockly-scripts start",
     "test": "blockly-scripts test"
   },
-  "main": "./dist/index.js",
-  "types": "./dist/index.d.ts",
-  "unpkg": "./dist/index.js",
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/esm/index.js",
+  "unpkg": "./dist/esm/index.js",
+  "type": "module",
+  "engines": {
+    "node": ">=24"
+  },
   "author": "Blockly Team",
   "keywords": [
     "blockly",
@@ -39,6 +43,13 @@
     "dist",
     "src"
   ],
+  "exports": {
+    ".": {
+      "node":    {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"},
+      "import":  {"types": "./dist/esm/index.d.ts", "default": "./dist/esm/index.js"},
+      "require": {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"}
+    }
+  },
   "devDependencies": {
     "@blockly/dev-scripts": "^13.4.0",
     "@blockly/dev-tools": "^13.4.0",
diff --git a/packages/plugins/field-multilineinput/src/blocks/textMultiline.ts b/packages/plugins/field-multilineinput/src/blocks/textMultiline.ts
index 831c79ed10b..b553dbed27c 100644
--- a/packages/plugins/field-multilineinput/src/blocks/textMultiline.ts
+++ b/packages/plugins/field-multilineinput/src/blocks/textMultiline.ts
@@ -13,8 +13,8 @@ import {DartGenerator, Order as DartOrder} from 'blockly/dart';
 import {LuaGenerator, Order as LuaOrder} from 'blockly/lua';
 import {PhpGenerator, Order as PhpOrder} from 'blockly/php';
 import {PythonGenerator, Order as PythonOrder} from 'blockly/python';
-import {registerFieldMultilineInput} from '../field_multilineinput';
-import {Generators} from './generatorsType';
+import {registerFieldMultilineInput} from '../field_multilineinput.js';
+import {Generators} from './generatorsType.js';
 
 /** The name this block is registered under. */
 export const BLOCK_NAME = 'text_multiline';
diff --git a/packages/plugins/field-multilineinput/src/index.ts b/packages/plugins/field-multilineinput/src/index.ts
index 051fded12e4..b9f6c278af0 100644
--- a/packages/plugins/field-multilineinput/src/index.ts
+++ b/packages/plugins/field-multilineinput/src/index.ts
@@ -4,12 +4,12 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-import * as textMultiline from './blocks/textMultiline';
+import * as textMultiline from './blocks/textMultiline.js';
 
-export * from './field_multilineinput';
+export * from './field_multilineinput.js';
 
 // Re-export all parts of the block definition.
-export * as textMultiline from './blocks/textMultiline';
+export * as textMultiline from './blocks/textMultiline.js';
 
 // This package currently exports a single block. More may
 // be added later.
diff --git a/packages/plugins/field-multilineinput/test/block_test.mocha.js b/packages/plugins/field-multilineinput/test/block_test.mocha.js
index d60fd2cf156..4b533b129df 100644
--- a/packages/plugins/field-multilineinput/test/block_test.mocha.js
+++ b/packages/plugins/field-multilineinput/test/block_test.mocha.js
@@ -14,7 +14,7 @@ import {dartGenerator} from 'blockly/dart';
 import {phpGenerator} from 'blockly/php';
 import {pythonGenerator} from 'blockly/python';
 import {luaGenerator} from 'blockly/lua';
-import {installAllBlocks} from '../src/index';
+import {installAllBlocks} from '../src/index.js';
 import {assert} from 'chai';
 
 const blockJson = {
diff --git a/packages/plugins/field-multilineinput/test/field_multilineinput_test.mocha.js b/packages/plugins/field-multilineinput/test/field_multilineinput_test.mocha.js
index cbfcfe5b873..52a0bf0a30c 100644
--- a/packages/plugins/field-multilineinput/test/field_multilineinput_test.mocha.js
+++ b/packages/plugins/field-multilineinput/test/field_multilineinput_test.mocha.js
@@ -4,14 +4,15 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-const {testHelpers} = require('@blockly/dev-tools');
-const {
+import jsdomGlobal from 'jsdom-global';
+import {assert} from 'chai';
+import sinon from 'sinon';
+import * as Blockly from 'blockly';
+import {testHelpers} from '@blockly/dev-tools';
+import {
   FieldMultilineInput,
   registerFieldMultilineInput,
-} = require('../src/index');
-const Blockly = require('blockly');
-const {assert} = require('chai');
-const sinon = require('sinon');
+} from '../src/index.js';
 
 const {
   assertFieldValue,
@@ -150,7 +151,7 @@ suite('FieldMultilineInput', function () {
     };
 
     setup(function () {
-      this.jsdomCleanup = require('jsdom-global')(
+      this.jsdomCleanup = jsdomGlobal(
         '<!DOCTYPE html><div id="blocklyDiv"></div>',
       );
       // See https://github.com/RaspberryPiFoundation/blockly-samples/issues/2528.
diff --git a/packages/plugins/field-multilineinput/test/index.ts b/packages/plugins/field-multilineinput/test/index.ts
index 7977e561371..c7f093df924 100644
--- a/packages/plugins/field-multilineinput/test/index.ts
+++ b/packages/plugins/field-multilineinput/test/index.ts
@@ -15,7 +15,7 @@ import {phpGenerator} from 'blockly/php';
 import {pythonGenerator} from 'blockly/python';
 import {luaGenerator} from 'blockly/lua';
 import {createPlayground} from '@blockly/dev-tools';
-import {FieldMultilineInput, textMultiline} from '../src/index';
+import {FieldMultilineInput, textMultiline} from '../src/index.js';
 
 /**
  * An array of blocks that are defined only for the purposes of
diff --git a/packages/plugins/field-multilineinput/tsconfig.json b/packages/plugins/field-multilineinput/tsconfig.json
index 99858c525f1..a6e04369c08 100644
--- a/packages/plugins/field-multilineinput/tsconfig.json
+++ b/packages/plugins/field-multilineinput/tsconfig.json
@@ -1,14 +1,8 @@
 {
+  "extends": "@blockly/dev-scripts/config/tsconfig.base.json",
   "compilerOptions": {
     "rootDir": "./src",
-    "outDir": "dist",
-    "declaration": true,
-    "declarationMap": true,
-    "sourceMap": true,
-    "module": "es2015",
-    "moduleResolution": "bundler",
-    "target": "es6",
-    "strict": true
+    "outDir": "dist/esm"
   },
   // NOTE: `test/**/*` is automatically included in `blockly-scripts start`.
   // Only src matters for production builds.

From 4a912a99b0ac8b149319d0b145e56d8200b15954 Mon Sep 17 00:00:00 2001
From: lizschwab <liz.schwab@raspberrypi.org>
Date: Thu, 12 Nov 2026 12:40:08 -0800
Subject: [PATCH 4/5] feat: Update field-slider to ESM

---
 eslint.config.mjs                               |  1 +
 packages/plugins/field-slider/package.json      | 17 ++++++++++++++---
 packages/plugins/field-slider/src/index.ts      |  2 +-
 .../test/field_slider_test.mocha.js             | 12 ++++++------
 .../test/field_slider_test_helpers.mocha.js     | 13 +++++--------
 packages/plugins/field-slider/test/index.ts     |  2 +-
 packages/plugins/field-slider/tsconfig.json     | 10 ++--------
 7 files changed, 30 insertions(+), 27 deletions(-)

diff --git a/eslint.config.mjs b/eslint.config.mjs
index 687519845d3..da5cfd26521 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -424,6 +424,7 @@ export default defineConfig(
       'packages/plugins/field-dependent-dropdown/**',
       'packages/plugins/field-grid-dropdown/**',
       'packages/plugins/field-multilineinput/**',
+      'packages/plugins/field-slider/**',
       'packages/plugins/modal/**',
       'packages/plugins/theme-modern/**',
       'packages/plugins/typed-variable-modal/**',
diff --git a/packages/plugins/field-slider/package.json b/packages/plugins/field-slider/package.json
index 10c7cf641ef..293cb550911 100644
--- a/packages/plugins/field-slider/package.json
+++ b/packages/plugins/field-slider/package.json
@@ -11,9 +11,13 @@
     "start": "blockly-scripts start",
     "test": "blockly-scripts test"
   },
-  "main": "./dist/index.js",
-  "types": "./dist/index.d.ts",
-  "unpkg": "./dist/index.js",
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/esm/index.js",
+  "unpkg": "./dist/esm/index.js",
+  "type": "module",
+  "engines": {
+    "node": ">=24"
+  },
   "author": "Blockly Team",
   "keywords": [
     "blockly",
@@ -38,6 +42,13 @@
     "dist",
     "src"
   ],
+  "exports": {
+    ".": {
+      "node":    {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"},
+      "import":  {"types": "./dist/esm/index.d.ts", "default": "./dist/esm/index.js"},
+      "require": {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"}
+    }
+  },
   "devDependencies": {
     "@blockly/dev-scripts": "^13.4.0",
     "@blockly/dev-tools": "^13.4.0",
diff --git a/packages/plugins/field-slider/src/index.ts b/packages/plugins/field-slider/src/index.ts
index 7057226589a..9933642bf88 100644
--- a/packages/plugins/field-slider/src/index.ts
+++ b/packages/plugins/field-slider/src/index.ts
@@ -4,4 +4,4 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-export * from './field_slider';
+export * from './field_slider.js';
diff --git a/packages/plugins/field-slider/test/field_slider_test.mocha.js b/packages/plugins/field-slider/test/field_slider_test.mocha.js
index da28519c1a8..acd04e7c7db 100644
--- a/packages/plugins/field-slider/test/field_slider_test.mocha.js
+++ b/packages/plugins/field-slider/test/field_slider_test.mocha.js
@@ -4,14 +4,14 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-const {assert} = require('chai');
-const sinon = require('sinon');
-const {
+import {assert} from 'chai';
+import sinon from 'sinon';
+import {
   assertSliderField,
   assertSliderFieldDefault,
-} = require('./field_slider_test_helpers.mocha');
-const {testHelpers} = require('@blockly/dev-tools');
-const {FieldSlider} = require('../src/index');
+} from './field_slider_test_helpers.mocha.js';
+import {testHelpers} from '@blockly/dev-tools';
+import {FieldSlider} from '../src/index.js';
 
 const {
   assertFieldValue,
diff --git a/packages/plugins/field-slider/test/field_slider_test_helpers.mocha.js b/packages/plugins/field-slider/test/field_slider_test_helpers.mocha.js
index c3d2116d037..87470c43a61 100644
--- a/packages/plugins/field-slider/test/field_slider_test_helpers.mocha.js
+++ b/packages/plugins/field-slider/test/field_slider_test_helpers.mocha.js
@@ -4,9 +4,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-const {assert} = require('chai');
-const {assertFieldValue} = require('@blockly/dev-tools').testHelpers;
-const {FieldSlider} = require('../src/index');
+import {assert} from 'chai';
+import {testHelpers} from '@blockly/dev-tools';
+import {FieldSlider} from '../src/index.js';
 
 /**
  * Assert the slider field options.
@@ -23,7 +23,7 @@ function assertSliderField(
   expectedPrecision,
   expectedValue,
 ) {
-  assertFieldValue(sliderField, expectedValue);
+  testHelpers.assertFieldValue(sliderField, expectedValue);
   assert.equal(sliderField.getMin(), expectedMin, 'Min');
   assert.equal(sliderField.getMax(), expectedMax, 'Max');
   assert.equal(sliderField.getPrecision(), expectedPrecision, 'Precision');
@@ -36,7 +36,4 @@ function assertSliderFieldDefault(sliderField) {
   assertSliderField(sliderField, -Infinity, Infinity, 0, 0);
 }
 
-module.exports = {
-  assertSliderField,
-  assertSliderFieldDefault,
-};
+export {assertSliderField, assertSliderFieldDefault};
diff --git a/packages/plugins/field-slider/test/index.ts b/packages/plugins/field-slider/test/index.ts
index 0625e56592f..a8911abe699 100644
--- a/packages/plugins/field-slider/test/index.ts
+++ b/packages/plugins/field-slider/test/index.ts
@@ -11,7 +11,7 @@
 
 import * as Blockly from 'blockly';
 import {createPlayground} from '@blockly/dev-tools';
-import '../src/index';
+import '../src/index.js';
 
 /**
  * An array of blocks that are defined only for the purposes of
diff --git a/packages/plugins/field-slider/tsconfig.json b/packages/plugins/field-slider/tsconfig.json
index 99858c525f1..a6e04369c08 100644
--- a/packages/plugins/field-slider/tsconfig.json
+++ b/packages/plugins/field-slider/tsconfig.json
@@ -1,14 +1,8 @@
 {
+  "extends": "@blockly/dev-scripts/config/tsconfig.base.json",
   "compilerOptions": {
     "rootDir": "./src",
-    "outDir": "dist",
-    "declaration": true,
-    "declarationMap": true,
-    "sourceMap": true,
-    "module": "es2015",
-    "moduleResolution": "bundler",
-    "target": "es6",
-    "strict": true
+    "outDir": "dist/esm"
   },
   // NOTE: `test/**/*` is automatically included in `blockly-scripts start`.
   // Only src matters for production builds.

From c7785a6c844d058940bfb2f9282a1eaafb3d7bfb Mon Sep 17 00:00:00 2001
From: lizschwab <liz.schwab@raspberrypi.org>
Date: Thu, 12 Nov 2026 13:06:06 -0800
Subject: [PATCH 5/5] feat: Updated fixed-edges to ESM

---
 eslint.config.mjs                          |  1 +
 packages/plugins/fixed-edges/package.json  | 17 ++++++++++++++---
 packages/plugins/fixed-edges/test/index.js |  2 +-
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/eslint.config.mjs b/eslint.config.mjs
index da5cfd26521..52e7a152262 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -425,6 +425,7 @@ export default defineConfig(
       'packages/plugins/field-grid-dropdown/**',
       'packages/plugins/field-multilineinput/**',
       'packages/plugins/field-slider/**',
+      'packages/plugins/fixed-edges/**',
       'packages/plugins/modal/**',
       'packages/plugins/theme-modern/**',
       'packages/plugins/typed-variable-modal/**',
diff --git a/packages/plugins/fixed-edges/package.json b/packages/plugins/fixed-edges/package.json
index 2dca1be49af..d1a170a4df8 100644
--- a/packages/plugins/fixed-edges/package.json
+++ b/packages/plugins/fixed-edges/package.json
@@ -10,9 +10,13 @@
     "predeploy": "blockly-scripts predeploy",
     "start": "blockly-scripts start"
   },
-  "main": "./dist/index.js",
-  "module": "./src/index.js",
-  "unpkg": "./dist/index.js",
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/esm/index.js",
+  "unpkg": "./dist/esm/index.js",
+  "type": "module",
+  "engines": {
+    "node": ">=24"
+  },
   "author": "Blockly Team",
   "keywords": [
     "blockly",
@@ -37,6 +41,13 @@
     "dist",
     "src"
   ],
+  "exports": {
+    ".": {
+      "node":    {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"},
+      "import":  {"types": "./dist/esm/index.d.ts", "default": "./dist/esm/index.js"},
+      "require": {"types": "./dist/cjs/index.d.ts", "default": "./dist/cjs/index.js"}
+    }
+  },
   "devDependencies": {
     "@blockly/dev-scripts": "^13.4.0",
     "@blockly/dev-tools": "^13.4.0"
diff --git a/packages/plugins/fixed-edges/test/index.js b/packages/plugins/fixed-edges/test/index.js
index 6e9ecba01ef..efad1e2220e 100644
--- a/packages/plugins/fixed-edges/test/index.js
+++ b/packages/plugins/fixed-edges/test/index.js
@@ -10,7 +10,7 @@
 
 import * as Blockly from 'blockly';
 import {toolboxCategories, createPlayground} from '@blockly/dev-tools';
-import {FixedEdgesMetricsManager} from '../src/index';
+import {FixedEdgesMetricsManager} from '../src/index.js';
 
 /**
  * Create a workspace.