Add feature flag for polygon with unlimited polygon. (#1732)

## Summary:
Adding feature flag for the polygon unlimited sides work.

Issue: LEMS-1839

## Test plan:
Ideally no code should be effected by this new feature flag. This is here so future POC and rollout of experience is behind the proper flag.

Author: catandthemachines

Reviewers: benchristel, anakaren-rojas, nicolecomputer

Required Reviewers:

Approved By: benchristel

Checks: ✅ Publish npm snapshot (ubuntu-latest, 20.x), ✅ Lint, Typecheck, Format, and Test (ubuntu-latest, 20.x), ✅ Check for .changeset entries for all changed files (ubuntu-latest, 20.x), ✅ Cypress (ubuntu-latest, 20.x), ✅ Check builds for changes in size (ubuntu-latest, 20.x), ✅ Publish Storybook to Chromatic (ubuntu-latest, 20.x), ✅ gerald

Pull Request URL: #1732

.changeset/ninety-hairs-crash.md

@@ -0,0 +1,5 @@
+---
+"@khanacademy/perseus": patch
+---
+
+Adding Unlimited Polygon feature flag.

packages/perseus/src/types.ts

@@ -199,6 +199,8 @@ export const MafsGraphTypeFlags = [
     "ray",
     /** Enables the `polygon` interactive-graph type a fixed number of sides. */
     "polygon",
+    /** Enable the `unlimited-polygon` interactive graph type for an unlimited number of sides */
+    "unlimited-polygon",
     /** Enables the `circle` interactive-graph type.  */
     "circle",
     /** Enables the `quadratic` interactive-graph type.  */

packages/perseus/src/widgets/interactive-graph.tsx

@@ -2377,7 +2377,7 @@ export function shouldUseMafs(
                 // TODO(benchristel): add a feature flag for the "unlimited"
                 // case once we've implemented polygon graphs with unlimited
                 // sides
-                return false;
+                return Boolean(mafsFlags["unlimited-polygon"]);
             }
             return Boolean(mafsFlags["polygon"]);
         default:

packages/perseus/src/widgets/interactive-graphs/interactive-graph.test.tsx

@@ -215,6 +215,7 @@ describe("a mafs graph", () => {
         quadratic: quadraticQuestion,
         sinusoid: sinusoidQuestion,
         "unlimited-point": pointQuestion,
+        "unlimited-polygon": polygonQuestion,
     };
 
     const graphQuestionRenderersCorrect: {
@@ -231,6 +232,7 @@ describe("a mafs graph", () => {
         quadratic: quadraticQuestionWithDefaultCorrect,
         sinusoid: sinusoidQuestionWithDefaultCorrect,
         "unlimited-point": pointQuestionWithDefaultCorrect,
+        "unlimited-polygon": polygonQuestionDefaultCorrect,
     };
 
     describe.each(Object.entries(graphQuestionRenderers))(

packages/perseus/src/widgets/interactive-graphs/mafs-supported-graph-types.ts

@@ -10,6 +10,7 @@ export const mafsSupportedGraphTypes = [
     "quadratic",
     "sinusoid",
     "unlimited-point",
+    "unlimited-polygon",
 ] as const;
 
 export type MafsSupportedGraphType = (typeof mafsSupportedGraphTypes)[number];