Add support for waitForIt callback to be async (#255)

* Bump to version 0.6.0

Closes #254

__tests__/waitForIt/waitForIt.t.ts

@@ -10,6 +10,10 @@ describe("WaitForIt", () => {
     wait().until(() => true);
   });
 
+  it("should resolve when condition passes and callback returns a promise", () => {
+    wait().until(() => Promise.resolve(true));
+  });
+
   it("should reject when condition runs out of tries", async () => {
     await expect(wait().until(() => false)).rejects.toEqual(
       new Error("Condition was not met after 40 tries"),

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@kiwiproject/kiwi-test-js",
-  "version": "0.5.1",
+  "version": "0.6.0",
   "description": "kiwi-test-js is a test utility library. Most of these utilities are ports from the Java Kiwi-test library",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

src/waitForIt/waitForIt.ts

@@ -77,7 +77,7 @@ class WaitFor {
    * will be returned.
    * @param cb The function to check if the condition is true or false.
    */
-  until(cb: () => boolean): Promise<string> {
+  async until(cb: () => boolean | Promise<boolean>): Promise<string> {
     const totalTries = this.timeoutMs / this.pollIntervalMs;
 
     const aliasText = this.alias ? `with alias ${this.alias} ` : "";
@@ -91,8 +91,8 @@ class WaitFor {
     return new Promise((resolve, reject) => {
       let tries = 1;
 
-      const loop = () => {
-        if (cb.apply(this)) {
+      const processResult = (result: boolean) => {
+        if (result) {
           if (this.verbose) {
             console.log(
               `Condition ${aliasText}met after ${tries} of ${totalTries} tries`,
@@ -118,6 +118,17 @@ class WaitFor {
         }
       };
 
+      const loop = async () => {
+        const cbResult = cb.apply(this);
+
+        if (typeof cbResult === "boolean") {
+          processResult(cbResult);
+        } else {
+          const cbPromiseResult = await cbResult;
+          processResult(cbPromiseResult);
+        }
+      };
+
       if (this.pollDelayMs > 0) {
         setTimeout(loop, this.pollDelayMs);
       } else {