refactor(ulid): remove len argument from encodeTime() and `encode…

…Random()` (#5054)
denoland · Jun 17, 2024 · f86c10a · f86c10a
1 parent 635e062
commit f86c10a
Show file tree

Hide file tree

Showing 3 changed files with 21 additions and 36 deletions.
diff --git a/ulid/_util.ts b/ulid/_util.ts
@@ -16,26 +16,26 @@ function replaceCharAt(str: string, index: number, char: string) {
   return str.substring(0, index) + char + str.substring(index + 1);
 }
 
-export function encodeTime(now: number, len: number = TIME_LEN): string {
-  if (!Number.isInteger(now) || now < 0 || now > TIME_MAX) {
+export function encodeTime(timestamp: number): string {
+  if (!Number.isInteger(timestamp) || timestamp < 0 || timestamp > TIME_MAX) {
     throw new RangeError(
-      "Time must be a positive integer less than " + TIME_MAX,
+      `Time must be a positive integer less than ${TIME_MAX}`,
     );
   }
   let str = "";
-  for (; len > 0; len--) {
-    const mod = now % ENCODING_LEN;
+  for (let len = TIME_LEN; len > 0; len--) {
+    const mod = timestamp % ENCODING_LEN;
     str = ENCODING[mod] + str;
-    now = (now - mod) / ENCODING_LEN;
+    timestamp = Math.floor(timestamp / ENCODING_LEN);
   }
   return str;
 }
 
-export function encodeRandom(len: number): string {
+export function encodeRandom(): string {
   let str = "";
-  const randomBytes = crypto.getRandomValues(new Uint8Array(len));
-  for (const randomByte of randomBytes) {
-    str += ENCODING[randomByte % ENCODING_LEN];
+  const bytes = crypto.getRandomValues(new Uint8Array(RANDOM_LEN));
+  for (const byte of bytes) {
+    str += ENCODING[byte % ENCODING_LEN];
   }
   return str;
 }
@@ -67,10 +67,10 @@ export function monotonicFactory(encodeRand = encodeRandom): ULID {
   return function ulid(seedTime: number = Date.now()): string {
     if (seedTime <= lastTime) {
       const incrementedRandom = (lastRandom = incrementBase32(lastRandom));
-      return encodeTime(lastTime, TIME_LEN) + incrementedRandom;
+      return encodeTime(lastTime) + incrementedRandom;
     }
     lastTime = seedTime;
-    const newRandom = (lastRandom = encodeRand(RANDOM_LEN));
-    return encodeTime(seedTime, TIME_LEN) + newRandom;
+    const newRandom = (lastRandom = encodeRand());
+    return encodeTime(seedTime) + newRandom;
   };
 }
diff --git a/ulid/mod.ts b/ulid/mod.ts
@@ -50,7 +50,6 @@ import {
   ENCODING,
   ENCODING_LEN,
   monotonicFactory,
-  RANDOM_LEN,
   TIME_LEN,
   TIME_MAX,
   ULID_LEN,
@@ -175,5 +174,5 @@ export function monotonicUlid(seedTime: number = Date.now()): string {
  * @returns A ULID.
  */
 export function ulid(seedTime: number = Date.now()): string {
-  return encodeTime(seedTime, TIME_LEN) + encodeRandom(RANDOM_LEN);
+  return encodeTime(seedTime) + encodeRandom();
 }
diff --git a/ulid/test.ts b/ulid/test.ts
@@ -9,10 +9,9 @@ import { decodeTime, monotonicUlid, ulid } from "./mod.ts";
 import {
   encodeRandom,
   encodeTime,
-  ENCODING,
-  ENCODING_LEN,
   incrementBase32,
   monotonicFactory,
+  RANDOM_LEN,
 } from "./_util.ts";
 
 Deno.test("incrementBase32()", async (t) => {
@@ -46,28 +45,20 @@ Deno.test("incrementBase32()", async (t) => {
 
 Deno.test("encodeTime()", async (t) => {
   await t.step("should return expected encoded result", () => {
-    assertEquals("01ARYZ6S41", encodeTime(1469918176385, 10));
-  });
-
-  await t.step("should change length properly", () => {
-    assertEquals("0001AS99AA60", encodeTime(1470264322240, 12));
-  });
-
-  await t.step("should truncate time if not enough length", () => {
-    assertEquals("AS4Y1E11", encodeTime(1470118279201, 8));
+    assertEquals("01ARYZ6S41", encodeTime(1469918176385));
   });
 
   await t.step("should throw an error", async (t) => {
     await t.step("if time greater than (2 ^ 48) - 1", () => {
       assertThrows(() => {
-        encodeTime(Math.pow(2, 48), 8);
+        encodeTime(Math.pow(2, 48));
       }, Error);
     });
 
     await t.step("if time is not a number", () => {
       assertThrows(() => {
         // deno-lint-ignore no-explicit-any
-        encodeTime("test" as any, 3);
+        encodeTime("test" as any);
       }, Error);
     });
 
@@ -93,7 +84,7 @@ Deno.test("encodeTime()", async (t) => {
 
 Deno.test("encodeRandom()", async (t) => {
   await t.step("should return correct length", () => {
-    assertEquals(12, encodeRandom(12).length);
+    assertEquals(RANDOM_LEN, encodeRandom().length);
   });
 });
 
@@ -146,13 +137,8 @@ Deno.test("ulid()", async (t) => {
 });
 
 Deno.test("monotonicUlid() handles monotonicity", async (t) => {
-  function encodeRandom(len: number): string {
-    let str = "";
-    const randomBytes = new Array(len).fill(30);
-    for (let i = 0; i < len; i++) {
-      str += ENCODING[randomBytes[i] % ENCODING_LEN];
-    }
-    return str;
+  function encodeRandom(): string {
+    return "YYYYYYYYYYYYYYYY";
   }
 
   await t.step("without seedTime", async (t) => {