keep old impl in test as reference; minor changes

src/CharWidth.test.ts

@@ -78,8 +78,8 @@ describe('getStringCellWidth', function(): void {
   // TODO: multiline tests once #1685 is resolved
 });
 
-describe('wcwidth regression', function(): void {
-  // TODO: remove with one of the next releases
+it('wcwidth should match all values from the old implementation', function(): void {
+  // old implementation
   const wcwidthOld = (function(opts: {nul: number, control: number}): (ucs: number) => number {
     // extracted from https://www.cl.cam.ac.uk/%7Emgk25/ucs/wcwidth.c
     // combining characters
@@ -247,9 +247,8 @@ describe('wcwidth regression', function(): void {
     };
   })({nul: 0, control: 0}); // configurable options
 
-  it('equality of old and new impl', function(): void {
-    for (let i = 0; i < 65536; ++i) {
-      assert.equal(wcwidth(i), wcwidthOld(i), `mismatch for i: ${i}`);
-    }
-  });
+  // test full BMP range old vs new implmenetation
+  for (let i = 0; i < 65536; ++i) {
+    assert.equal(wcwidth(i), wcwidthOld(i), `mismatch for i: ${i}`);
+  }
 });

src/CharWidth.ts

@@ -90,7 +90,6 @@ export const wcwidth = (function(opts: {nul: number, control: number}): (ucs: nu
     const control = opts.control | 0;
 
     // create lookup table for BMP plane
-    // TODO: make callable/configurable from UnicodeManager
     const table = new Uint8Array(65536);
     table.fill(1);
     table[0] = opts.nul;

src/InputHandler.ts

@@ -327,7 +327,6 @@ export class InputHandler extends Disposable implements IInputHandler {
   public print(data: string, start: number, end: number): void {
     let char: string;
     let code: number;
-    let second: number;
     let chWidth: number;
     const buffer: IBuffer = this._terminal.buffer;
     const charset: ICharset = this._terminal.charset;
@@ -355,7 +354,7 @@ export class InputHandler extends Disposable implements IInputHandler {
           this._surrogateFirst = char;
           continue;
         }
-        second = data.charCodeAt(stringPosition);
+        const second = data.charCodeAt(stringPosition);
         // if the second part is in surrogate pair range create the high codepoint
         // otherwise fall back to UCS-2 behavior (handle codepoints independently)
         if (0xDC00 <= second && second <= 0xDFFF) {