refactor: decouple Console implementation from stdout (#4899)

When creating a console instance, one must pass "printFunc" arg
which is used internally by Console to output messages.

Due to numerous refactors there was a single method ("console.clear()")
that used "Deno.stdout" instead of "printFunc".

This commit unifies how "Console" outpus message, by using 
"printFunc" in all methods; consequently "Deno.stdout" is no longer
imported in "cli/js/console.ts" making it a standalone module that doesn't
depend on any CLI-specific APIs.

2 files changed, 6 insertions, 32 deletions

diff --git a/cli/js/tests/console_test.ts b/cli/js/tests/console_test.ts
index 43378e2ca..bceee9419 100644
--- a/cli/js/tests/console_test.ts
+++ b/cli/js/tests/console_test.ts
@@ -5,8 +5,6 @@ import { assert, assertEquals, unitTest } from "./test_util.ts";
 // in order to "trick" TypeScript.
 const {
   inspect,
-  writeSync,
-  stdout,
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
 } = Deno as any;
 
@@ -744,21 +742,10 @@ unitTest(function consoleTestError(): void {
 });
 
 unitTest(function consoleTestClear(): void {
-  const stdoutWriteSync = stdout.writeSync;
-  const uint8 = new TextEncoder().encode("\x1b[1;1H" + "\x1b[0J");
-  let buffer = new Uint8Array(0);
-
-  stdout.writeSync = (u8: Uint8Array): Promise<number> => {
-    const tmp = new Uint8Array(buffer.length + u8.length);
-    tmp.set(buffer, 0);
-    tmp.set(u8, buffer.length);
-    buffer = tmp;
-
-    return writeSync(stdout.rid, u8);
-  };
-  console.clear();
-  stdout.writeSync = stdoutWriteSync;
-  assertEquals(buffer, uint8);
+  mockConsole((console, out) => {
+    console.clear();
+    assertEquals(out.toString(), "\x1b[1;1H" + "\x1b[0J");
+  });
 });
 
 // Test bound this issue
diff --git a/cli/js/web/console.ts b/cli/js/web/console.ts
index 061147887..5544ded3c 100644
--- a/cli/js/web/console.ts
+++ b/cli/js/web/console.ts
@@ -1,8 +1,5 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 import { isTypedArray, TypedArray } from "./util.ts";
-import { TextEncoder } from "./text_encoding.ts";
-import { SyncWriter } from "../io.ts";
-import { stdout } from "../files.ts";
 import { cliTable } from "./console_table.ts";
 import { exposeForTest } from "../internals.ts";
 import { PromiseState } from "./promise.ts";
@@ -39,16 +36,6 @@ export class CSI {
 
 /* eslint-disable @typescript-eslint/no-use-before-define */
 
-function cursorTo(stream: SyncWriter, _x: number, _y?: number): void {
-  const uint8 = new TextEncoder().encode(CSI.kClear);
-  stream.writeSync(uint8);
-}
-
-function clearScreenDown(stream: SyncWriter): void {
-  const uint8 = new TextEncoder().encode(CSI.kClearScreenDown);
-  stream.writeSync(uint8);
-}
-
 function getClassInstanceName(instance: unknown): string {
   if (typeof instance !== "object") {
     return "";
@@ -934,8 +921,8 @@ export class Console {
 
   clear = (): void => {
     this.indentLevel = 0;
-    cursorTo(stdout, 0, 0);
-    clearScreenDown(stdout);
+    this.#printFunc(CSI.kClear, false);
+    this.#printFunc(CSI.kClearScreenDown, false);
   };
 
   trace = (...args: unknown[]): void => {