Move stdin echoing to BufferedIO

src/buffered_io.ts

@@ -1,5 +1,5 @@
 import { IOutputCallback } from './callback';
-import { OutputFlag, Termios } from './termios';
+import { InputFlag, LocalFlag, OutputFlag, Termios } from './termios';
 
 /**
  * Classes to deal with buffered IO between main worker and web worker. Both have access to the same
@@ -280,13 +280,15 @@ export class WorkerBufferedIO extends BufferedIO {
 
   read(): number[] {
     Atomics.wait(this._readArray, READ_MAIN, this._readCount);
-    const ret = this._loadFromSharedArrayBuffer();
+    const read = this._loadFromSharedArrayBuffer();
     this._readCount++;
 
     // Notify main worker that character has been read and a new one can be stored.
     Atomics.store(this._readArray, READ_WORKER, this._readCount);
     Atomics.notify(this._readArray, READ_WORKER, 1);
 
+    const ret = this._processReadChars(read);
+    this._maybeEchoToOutput(ret);
     return ret;
   }
 
@@ -318,6 +320,66 @@ export class WorkerBufferedIO extends BufferedIO {
     }
   }
 
+  _maybeEchoToOutput(chars: number[]): void {
+    const NL = 10; // Linefeed \n
+    const echo = (this.termios.c_lflag & LocalFlag.ECHO) > 0;
+    const echoNL = (this.termios.c_lflag & LocalFlag.ECHONL) > 0;
+    if (!echo && !echoNL) {
+      return;
+    }
+
+    const ret: number[] = [];
+    for (const char of chars) {
+      switch (char) {
+        case NL:
+          ret.push(NL);
+          break;
+        case 4:
+          break;
+        default:
+          if (echo) {
+            ret.push(char);
+          }
+          break;
+      }
+    }
+
+    if (ret.length > 0) {
+      this.write(ret);
+    }
+  }
+
+  private _processReadChars(chars: number[]): number[] {
+    const NL = 10; // Linefeed \n
+    const CR = 13; // Carriage return \r
+
+    const ret: number[] = [];
+    for (const char of chars) {
+      switch (char) {
+        case CR:
+          if ((this.termios.c_iflag & InputFlag.IGNCR) === 0) {
+            if ((this.termios.c_iflag & InputFlag.ICRNL) > 0) {
+              ret.push(NL);
+            } else {
+              ret.push(CR);
+            }
+          }
+          break;
+        case NL:
+          if ((this.termios.c_iflag & InputFlag.INLCR) > 0) {
+            ret.push(CR);
+          } else {
+            ret.push(NL);
+          }
+          break;
+        default:
+          ret.push(char);
+          break;
+      }
+    }
+    return ret;
+  }
+
   private _processWriteChars(chars: Int8Array | number[]): number[] {
     const NL = 10; // Linefeed \n
     const CR = 13; // Carriage return \r

src/commands/wasm_command_runner.ts

@@ -32,16 +32,6 @@ export abstract class WasmCommandRunner implements ICommandRunner {
         _getCharBuffer = utf16codes.slice(1);
       }
 
-      if (stdin.isTerminal()) {
-        if (utf16 === 10) {
-          context.stdout.write('\n');
-          context.stdout.flush();
-        } else if (utf16 > 31 && utf16 !== 127) {
-          context.stdout.write(String.fromCharCode(...utf16codes));
-          context.stdout.flush();
-        }
-      }
-
       // What to do with length other than 1?
       if (utf16 === 4) {
         // EOT

test/tests/shell.test.ts

@@ -90,7 +90,7 @@ test.describe('Shell', () => {
         ]);
         return output.text;
       });
-      expect(output).toMatch(/^wc\r\nab {6}0 {7}1 {7}5\r\n/);
+      expect(output).toMatch('wc\r\na\x1B[Bb      0       1       5\r\n');
     });
 
     test('should support terminal stdin more than once', async ({ page }) => {