[Feature] Implement Buffer.alloc and Buffer.allocUnsafe, add tests (#4)

* [Feature] Implement Buffer.alloc and Buffer.allocUnsafe, add tests

* [Tests] Add Actual and Expected message

* [Tests] Add todos to implement when Try/Catch is supported

* [Cleanup] import Uint8Array manually to avoid @ts-ignore

Author: jtenner

assembly/buffer/index.ts

@@ -1,5 +1,25 @@
+import { BLOCK_MAXSIZE } from "rt/common";
+import { E_INVALIDLENGTH, E_INDEXOUTOFRANGE } from "util/error";
+import { Uint8Array } from "typedarray";
+
 export class Buffer extends Uint8Array {
   constructor(size: i32) {
     super(size);
   }
+
+  public static alloc(size: i32): Buffer {
+    return new Buffer(size);
+  }
+
+  @unsafe public static allocUnsafe(size: i32): Buffer {
+    // Node throws an error if size is less than 0
+    if (u32(size) > BLOCK_MAXSIZE) throw new RangeError(E_INVALIDLENGTH);
+    let buffer = __alloc(size, idof<ArrayBuffer>());
+    // This retains the pointer to the result Buffer.
+    let result = changetype<Buffer>(__alloc(offsetof<Buffer>(), idof<Buffer>()));
+    result.data = changetype<ArrayBuffer>(buffer);
+    result.dataStart = changetype<usize>(buffer);
+    result.dataLength = size;
+    return result;
+  }
 }

assembly/index.ts

@@ -1 +1,3 @@
+/// <reference path="../node_modules/assemblyscript/std/assembly/rt/index.d.ts" />
+
 export { Buffer } from "./buffer";

assembly/node.d.ts

@@ -1,3 +1,6 @@
 declare class Buffer extends Uint8Array {
-
+  /** This method allocates a new Buffer of indicated size. All of the data is zeroed. */
+  static alloc(size: i32): Buffer;
+  /** This method allocates a new Buffer of indicated size. This is unsafe because the data is not zeroed. */
+  static allocUnsafe(size: i32): Buffer;
 }

tests/.gitignore

@@ -0,0 +1 @@
+*.wat

tests/buffer.spec.ts

@@ -9,6 +9,7 @@
  *   });
  * });
  */
+import { BLOCK_MAXSIZE } from "rt/common";
 
 describe("buffer", () => {
   test("#constructor", () => {
@@ -17,5 +18,28 @@ describe("buffer", () => {
     let myBuffer = new Buffer(10);
     expect<ArrayBuffer>(myBuffer.buffer).toBeTruthy();
     expect<ArrayBuffer>(myBuffer.buffer).toHaveLength(10);
+    // TODO: expectFn(() => { new Buffer(-1); }).toThrow();
+    // TODO: expectFn(() => { new Buffer(BLOCK_MAXSIZE + 1); }).toThrow();
+  });
+
+  test("#alloc", () => {
+    expect<Buffer>(Buffer.alloc(10)).toBeTruthy();
+    expect<Buffer>(Buffer.alloc(10)).toHaveLength(10);
+    let buff = Buffer.alloc(100);
+    for (let i = 0; i < buff.length; i++) expect<u8>(buff[i]).toBe(0);
+    expect<ArrayBuffer>(buff.buffer).not.toBeNull();
+    expect<u32>(buff.byteLength).toBe(100);
+    // TODO: expectFn(() => { Buffer.alloc(-1); }).toThrow();
+    // TODO: expectFn(() => { Buffer.alloc(BLOCK_MAXSIZE + 1); }).toThrow();
+  });
+
+  test("#allocUnsafe", () => {
+    expect<Buffer>(Buffer.allocUnsafe(10)).toBeTruthy();
+    expect<Buffer>(Buffer.allocUnsafe(10)).toHaveLength(10);
+    let buff = Buffer.allocUnsafe(100);
+    expect<ArrayBuffer>(buff.buffer).not.toBeNull();
+    expect<u32>(buff.byteLength).toBe(100);
+    // TODO: expectFn(() => { Buffer.allocUnsafe(-1); }).toThrow();
+    // TODO: expectFn(() => { Buffer.allocUnsafe(BLOCK_MAXSIZE + 1); }).toThrow();
   });
 });

tests/node.js

@@ -37,9 +37,13 @@ class Reporter extends EmptyReporter {
   }
 
   onTestFinish(group, test) {
-    if (test.pass) process.stdout.write("Test      : " + group.name + " -> " + test.name + " ✔ PASS");
-    else           process.stdout.write("Test      : " + group.name + " -> " + test.name + " ❌ FAIL");
-    process.stdout.write("\n");
+    if (test.pass) process.stdout.write("Test      : " + group.name + " -> " + test.name + " ✔ PASS\n");
+    else           process.stdout.write("Test      : " + group.name + " -> " + test.name + " ❌ FAIL\n");
+
+    if (!test.pass) {
+      process.stdout.write("Actual    : " + test.actual.message + "\n");
+      process.stdout.write("Expected  : " + test.expected.message + "\n");
+    }
 
     if (test.logs.length > 0) {
       test.logs.forEach((e, i) => {
@@ -49,7 +53,10 @@ class Reporter extends EmptyReporter {
       process.stdout.write("\n");
     }
   }
-  onFinish() {
+  onFinish(context) {
+    const passed = context.testGroups.filter(e => !e.pass).length === 0;
+    if (passed) process.stdout.write("Suite     : ✔ PASS");
+    else           process.stdout.write("Suite     : ❌ FAIL");
     process.stdout.write("\n");
   }
 }