heygen-com · vanceingalls · Jun 12, 2026
diff --git a/packages/core/package.json b/packages/core/package.json
@@ -74,6 +74,14 @@
       "import": "./src/parsers/gsapParser.ts",
       "types": "./src/parsers/gsapParser.ts"
     },
+    "./gsap-parser-acorn": {
+      "import": "./src/parsers/gsapParserAcorn.ts",
+      "types": "./src/parsers/gsapParserAcorn.ts"
+    },
+    "./gsap-writer-acorn": {
+      "import": "./src/parsers/gsapWriterAcorn.ts",
+      "types": "./src/parsers/gsapWriterAcorn.ts"
+    },
     "./gsap-constants": {
       "import": "./src/parsers/gsapConstants.ts",
       "types": "./src/parsers/gsapConstants.ts"
@@ -153,6 +161,14 @@
         "import": "./dist/parsers/gsapParser.js",
         "types": "./dist/parsers/gsapParser.d.ts"
       },
+      "./gsap-parser-acorn": {
+        "import": "./dist/parsers/gsapParserAcorn.js",
+        "types": "./dist/parsers/gsapParserAcorn.d.ts"
+      },
+      "./gsap-writer-acorn": {
+        "import": "./dist/parsers/gsapWriterAcorn.js",
+        "types": "./dist/parsers/gsapWriterAcorn.d.ts"
+      },
       "./gsap-constants": {
         "import": "./dist/parsers/gsapConstants.js",
         "types": "./dist/parsers/gsapConstants.d.ts"

diff --git a/packages/core/src/parsers/gsapParser.acorn.test.ts b/packages/core/src/parsers/gsapParser.acorn.test.ts
@@ -1,4 +1,4 @@
-// fallow-ignore-file duplication
+// fallow-ignore-file code-duplication
 /**
  * T6b — acorn vs golden differential harness.
  *

diff --git a/packages/core/src/parsers/gsapParserAcorn.full.test.ts b/packages/core/src/parsers/gsapParserAcorn.full.test.ts
@@ -1,4 +1,4 @@
-// fallow-ignore-file duplication
+// fallow-ignore-file code-duplication
 /**
  * T6d: parse-parity suite — runs the full gsapParser.test.ts parse scenarios
  * against parseGsapScriptAcorn.  Write-path tests are it.skip'd; those live
@@ -912,3 +912,140 @@ describe("native GSAP keyframes parsing", () => {
     expect(Object.keys(anim.properties)).toHaveLength(0);
   });
 });
+
+// ── motionPath parsing ────────────────────────────────────────────────────────
+
+describe("motionPath parsing", () => {
+  it("parses motionPath with waypoint array and curviness", () => {
+    const script = `
+      const tl = gsap.timeline({ paused: true });
+      tl.to("#el", {
+        motionPath: {
+          path: [{x: 0, y: 0}, {x: 200, y: -100}, {x: 400, y: 50}],
+          curviness: 1.5
+        },
+        duration: 2
+      }, 0);
+    `;
+    const result = parseGsapScript(script);
+    expect(result.animations).toHaveLength(1);
+    const anim = result.animations[0];
+
+    expect(anim.arcPath).toBeDefined();
+    expect(anim.arcPath!.enabled).toBe(true);
+    expect(anim.arcPath!.segments).toHaveLength(2);
+    expect(anim.arcPath!.segments[0].curviness).toBe(1.5);
+    expect(anim.arcPath!.segments[1].curviness).toBe(1.5);
+
+    expect(anim.keyframes).toBeDefined();
+    expect(anim.keyframes!.keyframes).toHaveLength(3);
+    expect(anim.keyframes!.keyframes[0].properties.x).toBe(0);
+    expect(anim.keyframes!.keyframes[0].properties.y).toBe(0);
+    expect(anim.keyframes!.keyframes[1].properties.x).toBe(200);
+    expect(anim.keyframes!.keyframes[1].properties.y).toBe(-100);
+    expect(anim.keyframes!.keyframes[2].properties.x).toBe(400);
+    expect(anim.keyframes!.keyframes[2].properties.y).toBe(50);
+  });
+
+  it("parses motionPath with type cubic and explicit control points", () => {
+    const script = `
+      const tl = gsap.timeline({ paused: true });
+      tl.to("#el", {
+        motionPath: {
+          path: [
+            {x: 0, y: 0},
+            {x: 50, y: -80}, {x: 150, y: -120},
+            {x: 200, y: -100},
+            {x: 250, y: -80}, {x: 350, y: 30},
+            {x: 400, y: 50}
+          ],
+          type: "cubic"
+        },
+        duration: 2
+      }, 0);
+    `;
+    const result = parseGsapScript(script);
+    const anim = result.animations[0];
+
+    expect(anim.arcPath).toBeDefined();
+    expect(anim.arcPath!.segments).toHaveLength(2);
+
+    expect(anim.arcPath!.segments[0].cp1).toEqual({ x: 50, y: -80 });
+    expect(anim.arcPath!.segments[0].cp2).toEqual({ x: 150, y: -120 });
+
+    expect(anim.arcPath!.segments[1].cp1).toEqual({ x: 250, y: -80 });
+    expect(anim.arcPath!.segments[1].cp2).toEqual({ x: 350, y: 30 });
+
+    expect(anim.keyframes!.keyframes).toHaveLength(3);
+    expect(anim.keyframes!.keyframes[0].properties).toEqual({ x: 0, y: 0 });
+    expect(anim.keyframes!.keyframes[1].properties).toEqual({ x: 200, y: -100 });
+    expect(anim.keyframes!.keyframes[2].properties).toEqual({ x: 400, y: 50 });
+  });
+
+  it("parses motionPath with autoRotate", () => {
+    const script = `
+      const tl = gsap.timeline({ paused: true });
+      tl.to("#el", {
+        motionPath: {
+          path: [{x: 0, y: 0}, {x: 200, y: 100}],
+          autoRotate: true
+        },
+        duration: 1
+      }, 0);
+    `;
+    const result = parseGsapScript(script);
+    const anim = result.animations[0];
+    expect(anim.arcPath!.autoRotate).toBe(true);
+  });
+
+  it("merges motionPath waypoints into existing keyframes", () => {
+    const script = `
+      const tl = gsap.timeline({ paused: true });
+      tl.to("#el", {
+        motionPath: {
+          path: [{x: 0, y: 0}, {x: 200, y: 100}],
+          curviness: 2
+        },
+        keyframes: {
+          "0%": { opacity: 1 },
+          "100%": { opacity: 0 }
+        },
+        duration: 2
+      }, 0);
+    `;
+    const result = parseGsapScript(script);
+    const anim = result.animations[0];
+
+    expect(anim.arcPath).toBeDefined();
+    expect(anim.arcPath!.segments).toHaveLength(1);
+    expect(anim.arcPath!.segments[0].curviness).toBe(2);
+
+    expect(anim.keyframes!.keyframes).toHaveLength(2);
+    expect(anim.keyframes!.keyframes[0].properties).toEqual({ opacity: 1, x: 0, y: 0 });
+    expect(anim.keyframes!.keyframes[1].properties).toEqual({ opacity: 0, x: 200, y: 100 });
+  });
+
+  it("skips motionPath with fewer than 2 waypoints", () => {
+    const script = `
+      const tl = gsap.timeline({ paused: true });
+      tl.to("#el", {
+        motionPath: { path: [{x: 0, y: 0}] },
+        duration: 1
+      }, 0);
+    `;
+    const result = parseGsapScript(script);
+    expect(result.animations[0].arcPath).toBeUndefined();
+  });
+
+  it("tween without motionPath parses identically to before", () => {
+    const script = `
+      const tl = gsap.timeline({ paused: true });
+      tl.to("#el", { x: 100, y: 200, duration: 1 }, 0);
+    `;
+    const result = parseGsapScript(script);
+    const anim = result.animations[0];
+    expect(anim.arcPath).toBeUndefined();
+    expect(anim.properties.x).toBe(100);
+    expect(anim.properties.y).toBe(200);
+  });
+});
diff --git a/packages/core/src/parsers/gsapParserAcorn.ts b/packages/core/src/parsers/gsapParserAcorn.ts
@@ -1,4 +1,4 @@
-// fallow-ignore-file duplication
+// fallow-ignore-file code-duplication
 /**
  * Browser-safe GSAP read path — acorn + acorn-walk.
  *
@@ -1046,6 +1046,7 @@ function assignStableIds(anims: Omit<GsapAnimation, "id">[]): GsapAnimation[] {
 export interface ParsedGsapAcornForWrite {
   ast: any;
   timelineVar: string;
+  hasTimeline: boolean;
   located: Array<{ id: string; call: TweenCallInfo; animation: GsapAnimation }>;
 }
 
@@ -1075,7 +1076,7 @@ export function parseGsapScriptAcornForWrite(script: string): ParsedGsapAcornFor
       call,
       animation: animations[i]!,
     }));
-    return { ast, timelineVar, located };
+    return { ast, timelineVar, hasTimeline: detection.timelineVar !== null, located };
   } catch {
     return null;
   }

diff --git a/packages/core/src/parsers/gsapSerialize.ts b/packages/core/src/parsers/gsapSerialize.ts
@@ -91,6 +91,7 @@ export function serializeGsapAnimations(
       b.resolvedStart ?? (typeof b.position === "number" ? b.position : Number.MAX_SAFE_INTEGER);
     return aNum - bNum;
   });
+  // fallow-ignore-next-line complexity
   const lines = sorted.map((anim) => {
     const selector = `"${anim.targetSelector}"`;
     const props: Record<string, number | string> = { ...anim.properties };
@@ -198,7 +199,6 @@ export function getAnimationsForElementId(
 const FORBIDDEN_GSAP_PATTERNS: Array<{ pattern: RegExp; message: string }> = [
   { pattern: /\.call\s*\(/, message: "call() method not allowed" },
   { pattern: /\.add\s*\(/, message: "add() method not allowed" },
-  { pattern: /\.addLabel\s*\(/, message: "addLabel() method not allowed" },
   { pattern: /\.addPause\s*\(/, message: "addPause() method not allowed" },
   { pattern: /gsap\.registerEffect\s*\(/, message: "registerEffect() not allowed" },
   { pattern: /ScrollTrigger/, message: "ScrollTrigger not allowed" },
@@ -245,6 +245,7 @@ export function keyframesToGsapAnimations(
   const baseY = base?.y ?? 0;
   const baseScale = base?.scale ?? 1;
 
+  // fallow-ignore-next-line complexity
   sorted.forEach((kf, i) => {
     const absoluteTime = elementStartTime + kf.time;
     const isFirst = i === 0;
@@ -295,41 +296,44 @@ export function gsapAnimationsToKeyframes(
   const baseTimeEpsilon = 0.001;
   const baseValueEpsilon = 0.00001;
 
-  return animations
-    .filter((a) => validMethods.includes(a.method) && typeof a.position === "number")
-    .map((a) => {
-      const relativeTimeRaw = (a.position as number) - elementStartTime;
-      const time = clampTimeToZero ? Math.max(0, relativeTimeRaw) : relativeTimeRaw;
-
-      const properties: Partial<KeyframeProperties> = {};
-      for (const [key, value] of Object.entries(a.properties)) {
-        if (typeof value !== "number") continue;
-        if (key === "x") properties.x = value - baseX;
-        else if (key === "y") properties.y = value - baseY;
-        else if (key === "scale") {
-          properties.scale = baseScale !== 0 ? value / baseScale : value;
-        } else {
-          (properties as Record<string, number>)[key] = value;
+  return (
+    animations
+      .filter((a) => validMethods.includes(a.method) && typeof a.position === "number")
+      // fallow-ignore-next-line complexity
+      .map((a) => {
+        const relativeTimeRaw = (a.position as number) - elementStartTime;
+        const time = clampTimeToZero ? Math.max(0, relativeTimeRaw) : relativeTimeRaw;
+
+        const properties: Partial<KeyframeProperties> = {};
+        for (const [key, value] of Object.entries(a.properties)) {
+          if (typeof value !== "number") continue;
+          if (key === "x") properties.x = value - baseX;
+          else if (key === "y") properties.y = value - baseY;
+          else if (key === "scale") {
+            properties.scale = baseScale !== 0 ? value / baseScale : value;
+          } else {
+            (properties as Record<string, number>)[key] = value;
+          }
         }
-      }
 
-      if (
-        skipBaseSet &&
-        a.method === "set" &&
-        time < baseTimeEpsilon &&
-        Object.values(properties).every(
-          (v) => typeof v === "number" && Math.abs(v) < baseValueEpsilon,
-        )
-      ) {
-        return null;
-      }
+        if (
+          skipBaseSet &&
+          a.method === "set" &&
+          time < baseTimeEpsilon &&
+          Object.values(properties).every(
+            (v) => typeof v === "number" && Math.abs(v) < baseValueEpsilon,
+          )
+        ) {
+          return null;
+        }
 
-      return {
-        id: a.id.replace(/^.*-kf-/, ""),
-        time,
-        properties: properties as KeyframeProperties,
-        ease: a.ease,
-      };
-    })
-    .filter((kf): kf is NonNullable<typeof kf> => kf !== null) as Keyframe[];
+        return {
+          id: a.id.replace(/^.*-kf-/, ""),
+          time,
+          properties: properties as KeyframeProperties,
+          ease: a.ease,
+        };
+      })
+      .filter((kf): kf is NonNullable<typeof kf> => kf !== null) as Keyframe[]
+  );
 }
diff --git a/packages/core/src/parsers/gsapWriter.acorn.test.ts b/packages/core/src/parsers/gsapWriter.acorn.test.ts
@@ -1,4 +1,4 @@
-// fallow-ignore-file duplication
+// fallow-ignore-file code-duplication
 /**
  * T6c — acorn write path with magic-string offset-splice.
  *