Merge pull request #967 from y-lohse/expose-better-getset-types

Add typing information to get/set proxy typing

package.json

@@ -46,7 +46,7 @@
     "rollup-plugin-terser": "7.0.2",
     "rollup-plugin-typescript2": "0.31.2",
     "ts-jest": "26.5.6",
-    "ts-node": "10.5.0",
+    "ts-node": "^10.9.1",
     "tslint": "6.1.3",
     "typescript": "4.3.5"
   }

src/engine/VariablesState.ts

@@ -18,8 +18,20 @@ import { throwNullException } from "./NullException";
 import { CallStack } from "./CallStack";
 import { StatePatch } from "./StatePatch";
 import { SimpleJson } from "./SimpleJson";
+import { InkList } from "./Story";
+import { Path } from "./Path";
 
-export class VariablesState {
+// Fake class wrapper around VariableState to have correct typing
+// when using the Proxy syntax in typescript
+function VariablesStateAccessor<T>(): new () => Pick<T, keyof T> {
+  return class {} as any;
+}
+
+type VariableStateValue = boolean | string | number | InkList | Path | null;
+
+export class VariablesState extends VariablesStateAccessor<
+  Record<string, any>
+>() {
   // The way variableChangedEvent is a bit different than the reference implementation.
   // Originally it uses the C# += operator to add delegates, but in js we need to maintain
   // an actual collection of delegates (ie. callbacks) to register a new one, there is a
@@ -70,7 +82,9 @@ export class VariablesState {
   // the original code uses a magic getter and setter for global variables,
   // allowing things like variableState['varname]. This is not quite possible
   // in js without a Proxy, so it is replaced with this $ function.
-  public $(variableName: string, value: any) {
+  public $(variableName: string): VariableStateValue;
+  public $(variableName: string, value: VariableStateValue): void;
+  public $(variableName: string, value?: any) {
     if (typeof value === "undefined") {
       let varContents = null;
 
@@ -116,6 +130,7 @@ export class VariablesState {
     callStack: CallStack,
     listDefsOrigin: ListDefinitionsOrigin | null
   ) {
+    super();
     this._globalVariables = new Map();
     this._callStack = callStack;
     this._listDefsOrigin = listDefsOrigin;
@@ -138,8 +153,8 @@ export class VariablesState {
 
       return p;
     } catch (e) {
-      // thr proxy object is not available in this context. we should warn the
-      // dev but writting to the console feels a bit intrusive.
+      // the proxy object is not available in this context. we should warn the
+      // dev but writing to the console feels a bit intrusive.
       // console.log("ES6 Proxy not available - direct manipulation of global variables can't work, use $() instead.");
     }
   }