Add basic CompletionMapping and runEngine code

src/logic/completionMapping.ts

@@ -0,0 +1,49 @@
+import { Node } from "acorn";
+import { inspect } from "../../engine262/dist/engine262";
+
+import { CompletionRecord, CompletionTypes } from "../types/engine262-stubs";
+
+export interface ICompletionDetail {
+  start: number;
+  end: number;
+  completionType: CompletionTypes;
+  completionValueString: string;
+  completionTargetString: string | undefined;
+  completionValue: any;
+}
+
+export const completionMapping: {
+  completionDetails: ICompletionDetail[];
+  addCompletion(_: { node: Node; result: CompletionRecord }): void;
+  reset(): void;
+} = {
+  completionDetails: [],
+  addCompletion({ node, result }) {
+    const { start, end } = node;
+    const {
+      Type: completionType,
+      Value: completionValue,
+      Target: completionTarget,
+    } = result;
+
+    const completionValueString: string = inspect(completionValue);
+    const completionTargetString: string | undefined =
+      completionTarget !== undefined
+        ? inspect(completionTarget)
+        : completionTarget;
+
+    const obj = {
+      start,
+      end,
+      completionType,
+      completionValueString,
+      completionTargetString,
+      completionValue,
+    };
+
+    this.completionDetails.push(obj);
+  },
+  reset() {
+    this.completionDetails = [];
+  },
+};