feat(hub-common): adds a setProp utility

affects: @esri/hub-common

packages/common/src/objects/index.ts

@@ -8,3 +8,4 @@ export * from "./get-with-default";
 export * from "./remove-empty-props";
 export * from "./deep-string-replace";
 export * from "./merge-objects";
+export * from "./set-prop";

packages/common/src/objects/set-prop.ts

@@ -0,0 +1,22 @@
+/**
+ * Sets a deep object property, constructing the property path as necessary
+ *
+ * @param path - the path to the property we want to set
+ * @param val - the value we want to set it to
+ * @param obj - the target object
+ */
+export function setProp(path: string | string[], val: any, obj: any): boolean {
+  const props = Array.isArray(path) ? path : path.split(".");
+  if (props.length > 1) {
+    // does the object have this prop? if not, create it as an object
+    if (!obj.hasOwnProperty(props[0])) {
+      obj[props[0]] = {};
+    }
+    return setProp(props.slice(1), val, obj[props[0]]);
+    // recurse back into this, but with one less entry in the props
+  } else {
+    // this is the last one, the one we want to replace
+    obj[props[0]] = val;
+    return true;
+  }
+}

packages/common/test/objects/set-prop.test.ts

@@ -0,0 +1,21 @@
+import { setProp } from "../../src";
+
+describe("setProp", () => {
+  it("works with a string path", async () => {
+    const obj = {};
+    setProp("foo.bar", true, obj);
+    expect(obj).toEqual({ foo: { bar: true } });
+  });
+
+  it("works with an array path", async () => {
+    const obj = {};
+    setProp(["foo", "bar"], true, obj);
+    expect(obj).toEqual({ foo: { bar: true } });
+  });
+
+  it("uses an existing path when available", async () => {
+    const obj = { foo: { bar: false } };
+    setProp(["foo", "bar"], true, obj);
+    expect(obj).toEqual({ foo: { bar: true } });
+  });
+});