First pass at bufio.read tests.

Original: https://github.com/denoland/deno_std/commit/1eb57aa3948caf88e9064defc15e076b8a46fbd2

buffer.ts

@@ -4,7 +4,7 @@
 
 //import * as io from "./io";
 import { Reader, Writer, ReadResult } from "deno";
-import { assert } from "./util.ts";
+import { assert, copyBytes } from "./util.ts";
 
 // MIN_READ is the minimum ArrayBuffer size passed to a read call by
 // buffer.ReadFrom. As long as the Buffer has at least MIN_READ bytes beyond
@@ -13,18 +13,6 @@ import { assert } from "./util.ts";
 const MIN_READ = 512;
 const MAX_SIZE = 2 ** 32 - 2;
 
-// `off` is the offset into `dst` where it will at which to begin writing values
-// from `src`.
-// Returns the number of bytes copied.
-function copyBytes(dst: Uint8Array, src: Uint8Array, off = 0): number {
-  const r = dst.byteLength - off;
-  if (src.byteLength > r) {
-    src = src.subarray(0, r);
-  }
-  dst.set(src, off);
-  return src.byteLength;
-}
-
 /** A Buffer is a variable-sized buffer of bytes with read() and write()
  * methods. Based on https://golang.org/pkg/bytes/#Buffer
  */

buffer_test.ts

 // This code has been ported almost directly from Go's src/bytes/buffer_test.go
 // Copyright 2009 The Go Authors. All rights reserved. BSD license.
 // https://github.com/golang/go/blob/master/LICENSE
-import { test, assert, assertEqual } from "./test_util.ts";
-import { Buffer } from "deno";
+import {
+  test,
+  assert,
+  assertEqual
+} from "http://deno.land/x/testing/testing.ts";
+import { Buffer } from "./buffer.ts";
 
 // N controls how many iterations of certain checks are performed.
 const N = 100;
@@ -13,7 +17,7 @@ function init() {
   if (testBytes == null) {
     testBytes = new Uint8Array(N);
     for (let i = 0; i < N; i++) {
-      testBytes[i] = "a".charCodeAt(0) + (i % 26);
+      testBytes[i] = "a".charCodeAt(0) + i % 26;
     }
     const decoder = new TextDecoder();
     testString = decoder.decode(testBytes);

bufio.ts

+// Ported to Deno from:
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 import * as deno from "deno";
+import { assert, copyBytes } from "./util.ts";
 
 const DEFAULT_BUF_SIZE = 4096;
 const MIN_BUF_SIZE = 16;
 const MAX_CONSECUTIVE_EMPTY_READS = 100;
 
+export class ErrNegativeRead extends Error {
+  constructor() {
+    super("bufio: reader returned negative count from Read");
+    this.name = "ErrNegativeRead";
+  }
+}
+
 export class Reader implements deno.Reader {
   private buf: Uint8Array;
   private rd: deno.Reader; // Reader provided by caller.
@@ -16,7 +29,7 @@ export class Reader implements deno.Reader {
     if (size < MIN_BUF_SIZE) {
       size = MIN_BUF_SIZE;
     }
-    this._reset(new Uint8Array(size), rd)
+    this._reset(new Uint8Array(size), rd);
   }
 
   /** Returns the size of the underlying buffer in bytes. */
@@ -42,7 +55,7 @@ export class Reader implements deno.Reader {
     for (let i = MAX_CONSECUTIVE_EMPTY_READS; i > 0; i--) {
       const { nread, eof } = await this.rd.read(this.buf.subarray(this.w));
       if (nread < 0) {
-        throw Error("negative read");
+        throw new ErrNegativeRead();
       }
       this.w += nread;
       if (eof) {
@@ -69,9 +82,58 @@ export class Reader implements deno.Reader {
     this.lastCharSize = -1;
   }
 
+  /** reads data into p.
+   * It returns the number of bytes read into p.
+   * The bytes are taken from at most one Read on the underlying Reader,
+   * hence n may be less than len(p).
+   * At EOF, the count will be zero and err will be io.EOF.
+   * To read exactly len(p) bytes, use io.ReadFull(b, p).
+   */
   async read(p: ArrayBufferView): Promise<deno.ReadResult> {
-    throw Error("not implemented");
-    return { nread: 0, eof: false };
+    let rr: deno.ReadResult = { nread: p.byteLength, eof: false };
+    if (rr.nread === 0) {
+      return rr;
+    }
+
+    if (this.r === this.w) {
+      /*
+      if (this.err != null) {
+        throw this.readErr();
+      }
+      */
+      if (p.byteLength >= this.buf.byteLength) {
+        // Large read, empty buffer.
+        // Read directly into p to avoid copy.
+        rr = await this.rd.read(p);
+        if (rr.nread < 0) {
+          throw new ErrNegativeRead();
+        }
+        if (rr.nread > 0) {
+          this.lastByte = p[rr.nread - 1];
+          // this.lastRuneSize = -1;
+        }
+        return rr;
+      }
+      // One read.
+      // Do not use this.fill, which will loop.
+      this.r = 0;
+      this.w = 0;
+      rr = await this.rd.read(this.buf);
+      if (rr.nread < 0) {
+        throw new ErrNegativeRead();
+      }
+      if (rr.nread === 0) {
+        return rr;
+      }
+      this.w += rr.nread;
+    }
+
+    // copy as much as we can
+    rr.nread = copyBytes(p as Uint8Array, this.buf.subarray(this.r, this.w), 0);
+    this.r += rr.nread;
+    this.lastByte = this.buf[this.r - 1];
+    // this.lastRuneSize = -1;
+    return rr;
   }
 
   /** Returns the next byte [0, 255] or -1 if EOF. */
@@ -88,5 +150,3 @@ export class Reader implements deno.Reader {
     return c;
   }
 }
-
-

bufio_test.ts

+// Ported to Deno from:
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
 import * as deno from "deno";
 import { test, assertEqual } from "http://deno.land/x/testing/testing.ts";
 import * as bufio from "./bufio.ts";
@@ -30,3 +35,78 @@ test(async function bufioReaderSimple() {
   const s = await readBytes(b);
   assertEqual(s, data);
 });
+
+type ReadMaker = { name: string; fn: (r: deno.Reader) => deno.Reader };
+
+const readMakers: ReadMaker[] = [
+  { name: "full", fn: r => r }
+  /*
+  { name: "byte", fn(r) => new iotest.OneByteReader(r) },
+  { name: "half", fn(r) => new iotest.HalfReader(r) },
+  { name: "data+err", r => new iotest.DataErrReader(r) },
+  { name: "timeout", r => new iotest.TimeoutReader(r) },
+  */
+];
+
+// Call read to accumulate the text of a file
+async function reads(buf: bufio.Reader, m: number): Promise<string> {
+  const b = new Uint8Array(1000);
+  let nb = 0;
+  while (true) {
+    const { nread, eof } = await buf.read(b.subarray(nb, nb + m));
+    nb += nread;
+    if (eof) {
+      break;
+    }
+  }
+  const decoder = new TextDecoder();
+  return decoder.decode(b.subarray(0, nb));
+}
+
+type BufReader = { name: string; fn: (r: bufio.Reader) => Promise<string> };
+
+const bufreaders: BufReader[] = [
+  { name: "1", fn: (b: bufio.Reader) => reads(b, 1) }
+];
+
+const MIN_READ_BUFFER_SIZE = 16;
+const bufsizes: number[] = [
+  0,
+  MIN_READ_BUFFER_SIZE,
+  23,
+  32,
+  46,
+  64,
+  93,
+  128,
+  1024,
+  4096
+];
+
+test(async function bufioReader() {
+  const texts = new Array<string>(31);
+  let str = "";
+  let all = "";
+  for (let i = 0; i < texts.length - 1; i++) {
+    texts[i] = str + "\n";
+    all += texts[i];
+    str += String.fromCharCode(i % 26 + 97);
+  }
+  texts[texts.length - 1] = all;
+
+  for (let text of texts) {
+    for (let readmaker of readMakers) {
+      for (let bufreader of bufreaders) {
+        for (let bufsize of bufsizes) {
+          const read = readmaker.fn(stringsReader(text));
+          const buf = new bufio.Reader(read, bufsize);
+          const s = await bufreader.fn(buf);
+          const debugStr =
+            `reader=${readmaker.name} ` +
+            `fn=${bufreader.name} bufsize=${bufsize} want=${text} got=${s}`;
+          assertEqual(s, text, debugStr);
+        }
+      }
+    }
+  }
+});

file_server.ts

@@ -4,12 +4,12 @@ import { open, cwd } from "deno";
 const addr = "0.0.0.0:4500";
 const d = cwd();
 
-listenAndServe(addr, async (req) => {
+listenAndServe(addr, async req => {
   const filename = d + "/" + req.url;
   let res;
   try {
     res = { status: 200, body: open(filename) };
-  } catch(e) {
+  } catch (e) {
     res = { status: 500, body: "bad" };
   }
   req.respond(res);

http.ts

@@ -55,12 +55,12 @@ function readRequest(b: bufio.Reader): ServerRequest {
 
   // First line: GET /index.html HTTP/1.0
   const s = await tp.readLine();
-  const [ method, url, proto ] = parseRequestLine(s);
+  const [method, url, proto] = parseRequestLine(s);
   console.log("readRequest", method, url);
 }
 
 // Returns [method, url, proto]
-function parseRequestLine(line: string): [ string, string, string ] {
+function parseRequestLine(line: string): [string, string, string] {
   return line.split(" ", 3);
 }
 
@@ -69,4 +69,3 @@ export function listen(addr: string): Server {
   const s = new Server(listener);
   return s;
 }
-

util.ts

-
 export function assert(cond: boolean, msg = "assert") {
   if (!cond) {
     throw Error(msg);
   }
 }
+
+// `off` is the offset into `dst` where it will at which to begin writing values
+// from `src`.
+// Returns the number of bytes copied.
+export function copyBytes(dst: Uint8Array, src: Uint8Array, off = 0): number {
+  const r = dst.byteLength - off;
+  if (src.byteLength > r) {
+    src = src.subarray(0, r);
+  }
+  dst.set(src, off);
+  return src.byteLength;
+}