fix: wing console cannot be started (hangs) (#5924)

Wing Console used `tryGetResource` and expected it to return `undefined` if the node was not found, but #5821 did not respect this contract.

Fixed and added a test.

Fixes #5923 Fixes #5922

## Checklist

- [x] Title matches [Winglang's style guide](https://www.winglang.io/contributing/start-here/pull_requests#how-are-pull-request-titles-formatted)
- [x] Description explains motivation and solution
- [x] Tests added (always)
- [x] Docs updated (only required for features)
- [x] Added `pr/e2e-full` label if this feature requires end-to-end testing

*By submitting this pull request, I confirm that my contribution is made under the terms of the [Wing Cloud Contribution License](https://github.com/winglang/wing/blob/main/CONTRIBUTION_LICENSE.md)*.

libs/wingsdk/src/simulator/graph.ts

@@ -55,18 +55,18 @@ export class Graph<T extends Definition> {
     return Object.values(this.byPath);
   }
 
-  public find(path: string): Node<T> {
+  public tryFind(path: string): Node<T> | undefined {
     const node = this.byPath[path];
     if (!node) {
-      throw new Error(`node not found: ${path}`);
+      return undefined;
     }
 
     return node;
   }
 
   private recordDependency(consumer: string, producer: string) {
-    this.find(consumer).dependencies.add(producer);
-    this.find(producer).dependents.add(consumer);
+    this.tryFind(consumer)?.dependencies.add(producer);
+    this.tryFind(producer)?.dependents.add(consumer);
 
     // check for cyclic dependencies
     this.detectCycles(consumer);
@@ -91,7 +91,7 @@ export class Graph<T extends Definition> {
       visited.add(path);
       stack.add(path);
 
-      for (const dep of this.find(path).dependencies) {
+      for (const dep of this.tryFind(path)?.dependencies ?? []) {
         visit(dep);
       }
 

libs/wingsdk/src/simulator/simulator.ts

@@ -271,7 +271,7 @@ export class Simulator {
 
   private async startResources() {
     const retries: Record<string, number> = {};
-    const queue = this._model.graph.nodes.map(n => n.path);
+    const queue = this._model.graph.nodes.map((n) => n.path);
     while (queue.length > 0) {
       const top = queue.shift()!;
       try {
@@ -367,7 +367,7 @@ export class Simulator {
     }
 
     // first, stop all dependent resources
-    for (const consumer of this._model.graph.find(path)?.dependents ?? []) {
+    for (const consumer of this._model.graph.tryFind(path)?.dependents ?? []) {
       await this.stopResource(consumer);
     }
 
@@ -471,7 +471,11 @@ export class Simulator {
       path = `root${path}`;
     }
 
-    const def = this._model.graph.find(path).def;
+    const def = this._model.graph.tryFind(path)?.def;
+    if (!def) {
+      return undefined;
+    }
+
     const state = this.state[path];
 
     return {
@@ -677,7 +681,7 @@ export class Simulator {
     }
 
     // first lets make sure all my dependencies have been started (depth-first)
-    for (const d of this._model.graph.find(path).dependencies) {
+    for (const d of this._model.graph.tryFind(path)?.dependencies ?? []) {
       await this.startResource(d);
     }
 
@@ -806,7 +810,7 @@ export class Simulator {
    */
   private resolveTokens(obj: any): any {
     return resolveTokens(obj, (token) => {
-      const target = this._model.graph.find(token.path);
+      const target = this._model.graph.tryFind(token.path);
       if (!target) {
         throw new Error(
           `Could not resolve token "${token}" because the resource at path "${token.path}" does not exist.`

libs/wingsdk/test/simulator/graph.test.ts

@@ -11,12 +11,12 @@ test("two disconnected nodes", () => {
 
   expect(graph.nodes.length).toBe(2);
 
-  const a = graph.find("a");
+  const a = graph.tryFind("a")!;
   expect(a.def).toStrictEqual({ path: "a" });
   expect(Array.from(a.dependencies)).toStrictEqual([]);
   expect(Array.from(a.dependents)).toStrictEqual([]);
 
-  const b = graph.find("b");
+  const b = graph.tryFind("b")!;
   expect(b.def).toStrictEqual({ path: "b" });
   expect(Array.from(b.dependencies)).toStrictEqual([]);
   expect(Array.from(b.dependents)).toStrictEqual([]);
@@ -25,11 +25,11 @@ test("two disconnected nodes", () => {
 test("explicit deps", () => {
   const graph = new Graph([{ path: "a", deps: ["b"] }, { path: "b" }]);
 
-  const a = graph.find("a");
+  const a = graph.tryFind("a")!;
   expect(a.dependencies.size).toBe(1);
   expect(Array.from(a.dependencies)).toStrictEqual(["b"]);
 
-  const b = graph.find("b");
+  const b = graph.tryFind("b")!;
   expect(b.dependents.size).toBe(1);
   expect(Array.from(b.dependents)).toStrictEqual(["a"]);
 });
@@ -48,23 +48,28 @@ test("implicit deps", () => {
     { path: "d", props: { a: "${wsim#a#attrs.aaa}" }, deps: ["b"] },
   ]);
 
-  const a = graph.find("a");
+  const a = graph.tryFind("a")!;
   expect(Array.from(a.dependencies)).toStrictEqual(["b", "c/d/e"]);
   expect(Array.from(a.dependents)).toStrictEqual(["d"]);
 
-  const b = graph.find("b");
+  const b = graph.tryFind("b")!;
   expect(Array.from(b.dependencies)).toStrictEqual(["c/d/e"]);
   expect(Array.from(b.dependents)).toStrictEqual(["a", "d"]);
 
-  const c = graph.find("c/d/e");
+  const c = graph.tryFind("c/d/e")!;
   expect(Array.from(c.dependencies)).toStrictEqual([]);
   expect(Array.from(c.dependents)).toStrictEqual(["a", "b"]);
 
-  const d = graph.find("d");
+  const d = graph.tryFind("d")!;
   expect(Array.from(d.dependencies)).toStrictEqual(["b", "a"]);
   expect(Array.from(d.dependents)).toStrictEqual([]);
 });
 
+test("tryFind returns undefined if node does not exist", () => {
+  const graph = new Graph([]);
+  expect(graph.tryFind("a")).toBe(undefined);
+});
+
 test("fails on a direct cyclic dependency", () => {
   expect(() => {
     new Graph([

libs/wingsdk/test/simulator/simulator.test.ts

@@ -595,6 +595,13 @@ describe("in-place updates", () => {
   });
 });
 
+test("tryGetResource returns undefined if the resource not found", async () => {
+  const app = new SimApp();
+  const sim = await app.startSimulator();
+  expect(sim.tryGetResource("bang")).toBeUndefined();
+  expect(sim.tryGetResourceConfig("bing")).toBeUndefined();
+});
+
 function makeTest(
   scope: Construct,
   id: string,