Add LOOP and CONDITION test extension (#921)

does not work yet, but will soon

 - TurboWarp/scratch-vm#141
 - TurboWarp/scratch-vm#158

Author: GarboMuffin

website/test/loops.js

@@ -0,0 +1,71 @@
+// From https://github.com/TurboWarp/scratch-vm/pull/141
+(function (Scratch) {
+    "use strict";
+
+    class LoopsAndThings {
+        getInfo() {
+            return {
+                id: "loopsAndThings",
+                name: "Loops and things test",
+                blocks: [
+                    {
+                        opcode: "conditional",
+                        blockType: Scratch.BlockType.CONDITIONAL,
+                        text: "run branch [BRANCH] of",
+                        arguments: {
+                            BRANCH: {
+                                type: Scratch.ArgumentType.NUMBER,
+                                defaultValue: 1
+                            }
+                        },
+                        branchCount: 3
+                    },
+                    {
+                        opcode: "loop",
+                        blockType: Scratch.BlockType.LOOP,
+                        text: "my repeat [TIMES]",
+                        arguments: {
+                            TIMES: {
+                                type: Scratch.ArgumentType.NUMBER,
+                                defaultValue: 10
+                            }
+                        },
+                    },
+                    '---',
+                    {
+                        opcode: "testPromise",
+                        blockType: Scratch.BlockType.REPORTER,
+                        text: "return [VALUE] in a Promise",
+                        arguments: {
+                            VALUE: {
+                                type: Scratch.ArgumentType.STRING,
+                                defaultValue: ''
+                            }
+                        }
+                    }
+                ]
+            };
+        }
+
+        conditional({BRANCH}, util) {
+            return Scratch.Cast.toNumber(BRANCH);
+        }
+
+        loop({TIMES}, util) {
+            const times = Math.round(Scratch.Cast.toNumber(TIMES));
+            if (typeof util.stackFrame.loopCounter === "undefined") {
+                util.stackFrame.loopCounter = times;
+            }
+            util.stackFrame.loopCounter--;
+            if (util.stackFrame.loopCounter >= 0) {
+                return true;
+            }
+        }
+
+        testPromise({VALUE}) {
+            return Promise.resolve(VALUE);
+        }
+    }
+
+    Scratch.extensions.register(new LoopsAndThings());
+})(Scratch);