fix(std): Use Deno.errors where possible. (#4356)

4 files changed, 13 insertions, 20 deletions

diff --git a/std/io/bufio.ts b/std/io/bufio.ts
index fa0ba7e73..12b5c2d2b 100644
--- a/std/io/bufio.ts
+++ b/std/io/bufio.ts
@@ -21,11 +21,11 @@ export class BufferFullError extends Error {
   }
 }
 
-export class UnexpectedEOFError extends Error {
-  name = "UnexpectedEOFError";
+export class PartialReadError extends Deno.errors.UnexpectedEof {
+  name = "PartialReadError";
   partial?: Uint8Array;
   constructor() {
-    super("Unexpected EOF");
+    super("Encountered UnexpectedEof, data only partially read");
   }
 }
 
@@ -178,7 +178,7 @@ export class BufReader implements Reader {
           if (bytesRead === 0) {
             return Deno.EOF;
           } else {
-            throw new UnexpectedEOFError();
+            throw new PartialReadError();
           }
         }
         bytesRead += rr;
diff --git a/std/io/bufio_test.ts b/std/io/bufio_test.ts
index 75bd7b40e..d925175f1 100644
--- a/std/io/bufio_test.ts
+++ b/std/io/bufio_test.ts
@@ -15,7 +15,7 @@ import {
   BufReader,
   BufWriter,
   BufferFullError,
-  UnexpectedEOFError,
+  PartialReadError,
   readStringDelim,
   readLines
 } from "./bufio.ts";
@@ -369,9 +369,9 @@ Deno.test(async function bufReaderReadFull(): Promise<void> {
     const buf = new Uint8Array(6);
     try {
       await bufr.readFull(buf);
-      fail("readFull() should throw");
+      fail("readFull() should throw PartialReadError");
     } catch (err) {
-      assert(err instanceof UnexpectedEOFError);
+      assert(err instanceof PartialReadError);
       assert(err.partial instanceof Uint8Array);
       assertEquals(err.partial.length, 5);
       assertEquals(dec.decode(buf.subarray(0, 5)), "World");
diff --git a/std/io/iotest.ts b/std/io/iotest.ts
index 8d2cee6e2..1e922e33f 100644
--- a/std/io/iotest.ts
+++ b/std/io/iotest.ts
@@ -36,14 +36,7 @@ export class HalfReader implements Reader {
   }
 }
 
-export class ErrTimeout extends Error {
-  constructor() {
-    super("timeout");
-    this.name = "ErrTimeout";
-  }
-}
-
-/** TimeoutReader returns ErrTimeout on the second read
+/** TimeoutReader returns `Deno.errors.TimedOut` on the second read
  * with no data. Subsequent calls to read succeed.
  */
 export class TimeoutReader implements Reader {
@@ -53,7 +46,7 @@ export class TimeoutReader implements Reader {
   async read(p: Uint8Array): Promise<number | Deno.EOF> {
     this.count++;
     if (this.count === 2) {
-      throw new ErrTimeout();
+      throw new Deno.errors.TimedOut();
     }
     return this.r.read(p);
   }
diff --git a/std/io/ioutil.ts b/std/io/ioutil.ts
index 83d639463..cfcfdf794 100644
--- a/std/io/ioutil.ts
+++ b/std/io/ioutil.ts
@@ -1,5 +1,5 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
-import { BufReader, UnexpectedEOFError } from "./bufio.ts";
+import { BufReader } from "./bufio.ts";
 type Reader = Deno.Reader;
 type Writer = Deno.Writer;
 import { assert } from "../testing/asserts.ts";
@@ -37,7 +37,7 @@ export async function readShort(buf: BufReader): Promise<number | Deno.EOF> {
   const high = await buf.readByte();
   if (high === Deno.EOF) return Deno.EOF;
   const low = await buf.readByte();
-  if (low === Deno.EOF) throw new UnexpectedEOFError();
+  if (low === Deno.EOF) throw new Deno.errors.UnexpectedEof();
   return (high << 8) | low;
 }
 
@@ -46,7 +46,7 @@ export async function readInt(buf: BufReader): Promise<number | Deno.EOF> {
   const high = await readShort(buf);
   if (high === Deno.EOF) return Deno.EOF;
   const low = await readShort(buf);
-  if (low === Deno.EOF) throw new UnexpectedEOFError();
+  if (low === Deno.EOF) throw new Deno.errors.UnexpectedEof();
   return (high << 16) | low;
 }
 
@@ -57,7 +57,7 @@ export async function readLong(buf: BufReader): Promise<number | Deno.EOF> {
   const high = await readInt(buf);
   if (high === Deno.EOF) return Deno.EOF;
   const low = await readInt(buf);
-  if (low === Deno.EOF) throw new UnexpectedEOFError();
+  if (low === Deno.EOF) throw new Deno.errors.UnexpectedEof();
   const big = (BigInt(high) << 32n) | BigInt(low);
   // We probably should provide a similar API that returns BigInt values.
   if (big > MAX_SAFE_INTEGER) {