From 7e29bbef17bd247515137eaaf81174de6d599c8f Mon Sep 17 00:00:00 2001
From: GarboMuffin <muffin@mailbox.org>
Date: Mon, 22 May 2023 19:59:56 -0500
Subject: [PATCH] Add default extension URL for compatibility with Scratch Lab
 animated text projects

---
 src/serialization/sb3.js                      |  7 +-
 .../tw-default-extension-urls.js              | 11 +++
 test/integration/tw_default_extension_url.js  | 79 +++++++++++++++++++
 3 files changed, 95 insertions(+), 2 deletions(-)
 create mode 100644 src/serialization/tw-default-extension-urls.js
 create mode 100644 test/integration/tw_default_extension_url.js

diff --git a/src/serialization/sb3.js b/src/serialization/sb3.js
index c86faaea..59d2e1c9 100644
--- a/src/serialization/sb3.js
+++ b/src/serialization/sb3.js
@@ -16,6 +16,7 @@ const MathUtil = require('../util/math-util');
 const StringUtil = require('../util/string-util');
 const VariableUtil = require('../util/variable-util');
 const compress = require('./tw-compress-sb3');
+const defaultExtensionURLs = require('./tw-default-extension-urls');
 
 const {loadCostume} = require('../import/load-costume.js');
 const {loadSound} = require('../import/load-sound.js');
@@ -1338,7 +1339,7 @@ const replaceUnsafeCharsInVariableIds = function (targets) {
 const deserialize = function (json, runtime, zip, isSingleSprite) {
     const extensions = {
         extensionIDs: new Set(),
-        extensionURLs: new Map()
+        extensionURLs: new Map(Object.entries(defaultExtensionURLs))
     };
 
     // Store the origin field (e.g. project originated at CSFirst) so that we can save it again.
@@ -1350,7 +1351,9 @@ const deserialize = function (json, runtime, zip, isSingleSprite) {
 
     // Extract custom extension IDs, if they exist.
     if (json.extensionURLs) {
-        extensions.extensionURLs = new Map(Object.entries(json.extensionURLs));
+        for (const [id, url] of Object.entries(json.extensionURLs)) {
+            extensions.extensionURLs.set(id, url);
+        }
     }
 
     // First keep track of the current target order in the json,
diff --git a/src/serialization/tw-default-extension-urls.js b/src/serialization/tw-default-extension-urls.js
new file mode 100644
index 00000000..22f248e8
--- /dev/null
+++ b/src/serialization/tw-default-extension-urls.js
@@ -0,0 +1,11 @@
+// If a project uses an extension but does not specify a URL, it will default to
+// the URL given here, if any. This is useful for compatibility with other mods.
+
+const defaults = {
+    // Box2D (`griffpatch`) is not listed here because our extension is not actually
+    // compatible with the original version due to fields vs inputs.
+
+    text: 'https://extensions.turbowarp.org/lab/text.js'
+};
+
+module.exports = defaults;
diff --git a/test/integration/tw_default_extension_url.js b/test/integration/tw_default_extension_url.js
new file mode 100644
index 00000000..77b42ea9
--- /dev/null
+++ b/test/integration/tw_default_extension_url.js
@@ -0,0 +1,79 @@
+const {test} = require('tap');
+const {deserialize} = require('../../src/serialization/sb3');
+const Runtime = require('../../src/engine/runtime');
+
+// Note that at some point it is likely that this extension will break
+test('text extension defaults to URL', async t => {
+    t.plan(2);
+    const rt = new Runtime();
+    const deserialized = await deserialize({
+        targets: [
+            {
+                isStage: true,
+                name: 'Stage',
+                variables: {},
+                lists: {},
+                broadcasts: {},
+                blocks: {
+                    a: {
+                        opcode: 'text_clearText',
+                        next: null,
+                        parent: null,
+                        inputs: {},
+                        fields: {},
+                        shadow: false,
+                        topLevel: true,
+                        x: 203,
+                        y: 250
+                    },
+                    b: {
+                        opcode: 'pen_clear',
+                        next: null,
+                        parent: null,
+                        inputs: {},
+                        fields: {},
+                        shadow: false,
+                        topLevel: true,
+                        x: 203,
+                        y: 250
+                    },
+                    c: {
+                        opcode: 'griffpatch_doTick',
+                        next: null,
+                        parent: null,
+                        inputs: {},
+                        fields: {},
+                        shadow: false,
+                        topLevel: true,
+                        x: 203,
+                        y: 250
+                    }
+                },
+                comments: {},
+                currentCostume: 0,
+                costumes: [],
+                sounds: [],
+                volume: 100,
+                layerOrder: 0,
+                tempo: 60,
+                videoTransparency: 50,
+                videoState: 'on',
+                textToSpeechLanguage: null
+            }
+        ],
+        monitors: [],
+        // this list intentionally wrong to make sure we don't rely on its contents
+        extensions: [],
+        extensionURLs: {
+            griffpatch: 'https://extensions.turbowarp.org/fake-box2d-url.js'
+        },
+        meta: {
+            semver: '3.0.0',
+            vm: '0.2.0',
+            agent: ''
+        }
+    }, rt);
+    t.equal(deserialized.extensions.extensionURLs.get('text'), 'https://extensions.turbowarp.org/lab/text.js');
+    t.equal(deserialized.extensions.extensionURLs.get('griffpatch'), 'https://extensions.turbowarp.org/fake-box2d-url.js');
+    t.end();
+});