Support 2 operand $mul actions

Author: AnthonyFuller

src/index.ts

@@ -349,7 +349,8 @@ export function handleActions<Context>(
     }
 
     if (has("$mul")) {
-        let reference = input["$mul"][2]
+        // $mul can have 2 or 3 operands, 2 means multiply the context variable (1st operand) by the 2nd operand
+        let reference = input["$mul"][input["$mul"].length === 3 ? 2 : 0]
 
         const variableValue1 = findNamedChild(input["$mul"][0], context)
         const variableValue2 = findNamedChild(input["$mul"][1], context)

tests/math-actions.spec.ts

@@ -73,14 +73,24 @@ const data = {
     ],
     Mul1: [
         {
-            $mul: ["Context.Object", 5, "Context.Object"],
+            $mul: ["Context.Object", 5, "Context.Output"],
         },
         {
             Context: {
                 Object: 18,
             },
         },
     ],
+    Mul2: [
+        {
+            $mul: ["Context.Object", 10]
+        },
+        {
+            Context: {
+                Object: 42
+            }
+        }
+    ]
 }
 
 describe("$inc", () => {
@@ -118,9 +128,15 @@ describe("$dec", () => {
 })
 
 describe("$mul", () => {
-    it("can multiply a context object", () => {
+    it("can multiply a context object and store it in another", () => {
         const [sm, vars] = data.Mul1
         const r = handleActions(sm, vars)
-        assert.strictEqual(r.Context.Object, 90)
+        assert.strictEqual(r.Context.Output, 90)
+    })
+
+    it("can multiply a context object and store it in that object", () => {
+        const [sm, vars] = data.Mul2
+        const r= handleActions(sm, vars)
+        assert.strictEqual(r.Context.Object, 420)
     })
 })