Full PromisifiedStorage + Simplifications

src/core/client/embed/utils/__snapshots__/prefixStorage.spec.ts.snap

@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`should call clear 1`] = `"{\\"a\\":\\"0\\",\\"b\\":\\"1\\",\\"d\\":\\"3\\"}"`;

src/core/client/embed/utils/index.ts

@@ -1,2 +1,4 @@
 export { default as buildURL } from "./buildURL";
 export { default as ensureEndSlash } from "./ensureEndSlash";
+export { default as startsWith } from "./startsWith";
+export { default as prefixStorage } from "./prefixStorage";

src/core/client/embed/utils/prefixStorage.spec.ts

@@ -0,0 +1,79 @@
+import sinon from "sinon";
+import { createInMemoryStorage } from "../testUtils";
+import prefixStorage from "./prefixStorage";
+
+it("should get nth key", () => {
+  const storage = createInMemoryStorage({
+    a: "0",
+    b: "1",
+    "talk:c": "2",
+    d: "3",
+    "talk:e": "4",
+  });
+
+  const prefixed = prefixStorage(storage, "talk:");
+  expect(prefixed.key(0)).toBe("talk:c");
+  expect(prefixed.key(1)).toBe("talk:e");
+  expect(prefixed.key(2)).toBeNull();
+});
+
+it("should call clear", () => {
+  const storage = createInMemoryStorage({
+    a: "0",
+    b: "1",
+    "talk:c": "2",
+    d: "3",
+    "talk:e": "4",
+  });
+
+  const prefixed = prefixStorage(storage, "talk:");
+  prefixed.clear();
+  expect(storage.toString()).toMatchSnapshot();
+});
+
+it("should call length", () => {
+  const storage = createInMemoryStorage({
+    a: "0",
+    b: "1",
+    "talk:c": "2",
+    d: "3",
+    "talk:e": "4",
+  });
+
+  const prefixed = prefixStorage(storage, "talk:");
+  expect(prefixed.length).toBe(2);
+});
+
+it("should prefix setItem", () => {
+  const storage = {
+    setItem: sinon.mock().withArgs("talk:key", "value"),
+  };
+
+  const prefixed = prefixStorage(storage as any, "talk:");
+  prefixed.setItem("key", "value");
+  storage.setItem.verify();
+});
+
+it("should prefix removeItem", () => {
+  const storage = {
+    removeItem: sinon.mock().withArgs("talk:key"),
+  };
+
+  const prefixed = prefixStorage(storage as any, "talk:");
+  prefixed.removeItem("key");
+  storage.removeItem.verify();
+});
+
+it("should prefix getItem", () => {
+  const ret = "value";
+  const storage = {
+    getItem: sinon
+      .mock()
+      .withArgs("talk:key")
+      .returns(ret),
+  };
+
+  const prefixed = prefixStorage(storage as any, "talk:");
+  expect(prefixed.getItem("key")).toBe(ret);
+  (storage.getItem as any).verify();
+});

src/core/client/embed/utils/prefixStorage.ts

@@ -0,0 +1,66 @@
+import startsWith from "./startsWith";
+
+/**
+ * PrefixedStorage decorates a Storage and prefixes keys in
+ * getItem, setItem and removeItem with given prefix.
+ */
+class PrefixedStorage implements Storage {
+  private storage: Storage;
+  private prefix: string;
+
+  constructor(storage: Storage, prefix: string) {
+    this.storage = storage;
+    this.prefix = prefix;
+  }
+
+  get length() {
+    let count = 0;
+    for (let i = 0; i < this.storage.length; i++) {
+      if (startsWith(this.storage.key(i)!, this.prefix)) {
+        count++;
+      }
+    }
+    return count;
+  }
+
+  public clear() {
+    const toBeDeleted = [];
+    for (let i = 0; i < this.storage.length; i++) {
+      const key = this.storage.key(i)!;
+      if (startsWith(key, this.prefix)) {
+        toBeDeleted.push(key);
+      }
+    }
+    toBeDeleted.forEach(key => this.storage.removeItem(key));
+  }
+
+  public key(n: number) {
+    let count = 0;
+    for (let i = 0; i < this.storage.length; i++) {
+      const key = this.storage.key(i)!;
+      if (startsWith(key, this.prefix)) {
+        if (count === n) {
+          return key;
+        }
+        count++;
+      }
+    }
+    return null;
+  }
+
+  public getItem(key: string) {
+    return this.storage.getItem(`${this.prefix}${key}`);
+  }
+
+  public setItem(key: string, value: string) {
+    return this.storage.setItem(`${this.prefix}${key}`, value);
+  }
+
+  public removeItem(key: string) {
+    return this.storage.removeItem(`${this.prefix}${key}`);
+  }
+}
+
+export default function prefixStorage(storage: Storage, prefix: string) {
+  return new PrefixedStorage(storage, prefix);
+}

src/core/client/embed/utils/startsWith.spec.ts

@@ -0,0 +1,7 @@
+import startsWith from "./startsWith";
+
+it("should work correctly", () => {
+  const str1 = "Saturday night plans";
+  expect(startsWith(str1, "Sat")).toBe(true);
+  expect(startsWith(str1, "Sat", 3)).toBe(false);
+});

src/core/client/embed/utils/startsWith.ts

@@ -0,0 +1,4 @@
+/** A substitute for string.startsWith */
+export default function startsWith(str: string, search: string, pos?: number) {
+  return str.substr(!pos || pos < 0 ? 0 : +pos, search.length) === search;
+}