Implement lineHeight px format support

Co-authored-by: Tyriar <2193314+Tyriar@users.noreply.github.com>

src/common/services/OptionsService.lineHeight.test.ts

@@ -0,0 +1,86 @@
+/**
+ * Copyright (c) 2023 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { assert } from 'chai';
+import { OptionsService } from 'common/services/OptionsService';
+
+describe('OptionsService lineHeight', () => {
+  let optionsService: OptionsService;
+
+  beforeEach(() => {
+    optionsService = new OptionsService({});
+  });
+
+  describe('numeric lineHeight', () => {
+    it('should accept numeric values', () => {
+      optionsService.options.lineHeight = 1.5;
+      assert.equal(optionsService.rawOptions.lineHeight, 1.5);
+    });
+
+    it('should reject values less than 1', () => {
+      assert.throws(() => optionsService.options.lineHeight = 0.5);
+    });
+
+    it('should accept 1 as minimum value', () => {
+      optionsService.options.lineHeight = 1;
+      assert.equal(optionsService.rawOptions.lineHeight, 1);
+    });
+  });
+
+  describe('string lineHeight with px format', () => {
+    it('should accept px values', () => {
+      optionsService.options.lineHeight = '24px';
+      assert.equal(optionsService.rawOptions.lineHeight, '24px');
+    });
+
+    it('should accept decimal px values', () => {
+      optionsService.options.lineHeight = '23.5px';
+      assert.equal(optionsService.rawOptions.lineHeight, '23.5px');
+    });
+
+    it('should reject px values less than 1', () => {
+      assert.throws(() => optionsService.options.lineHeight = '0.5px');
+    });
+
+    it('should accept 1px as minimum value', () => {
+      optionsService.options.lineHeight = '1px';
+      assert.equal(optionsService.rawOptions.lineHeight, '1px');
+    });
+
+    it('should reject non-px string values', () => {
+      assert.throws(() => optionsService.options.lineHeight = '24' as any);
+      assert.throws(() => optionsService.options.lineHeight = '24em' as any);
+      assert.throws(() => optionsService.options.lineHeight = 'normal' as any);
+    });
+
+    it('should reject invalid px values', () => {
+      assert.throws(() => optionsService.options.lineHeight = 'invalidpx' as any);
+      assert.throws(() => optionsService.options.lineHeight = 'px' as any);
+    });
+  });
+
+  describe('invalid lineHeight types', () => {
+    it('should reject null', () => {
+      assert.throws(() => optionsService.options.lineHeight = null as any);
+    });
+
+    it('should reject undefined when explicitly set', () => {
+      assert.throws(() => optionsService.options.lineHeight = undefined as any);
+    });
+
+    it('should reject boolean values', () => {
+      assert.throws(() => optionsService.options.lineHeight = true as any);
+      assert.throws(() => optionsService.options.lineHeight = false as any);
+    });
+
+    it('should reject arrays', () => {
+      assert.throws(() => optionsService.options.lineHeight = [] as any);
+    });
+
+    it('should reject objects', () => {
+      assert.throws(() => optionsService.options.lineHeight = {} as any);
+    });
+  });
+});

src/common/services/OptionsService.ts

@@ -172,12 +172,31 @@ export class OptionsService extends Disposable implements IOptionsService {
       case 'cursorWidth':
         value = Math.floor(value);
         // Fall through for bounds check
-      case 'lineHeight':
       case 'tabStopWidth':
         if (value < 1) {
           throw new Error(`${key} cannot be less than 1, value: ${value}`);
         }
         break;
+      case 'lineHeight':
+        if (typeof value === 'string') {
+          // Handle 'px' format
+          if (value.endsWith('px')) {
+            const pxValue = parseFloat(value.slice(0, -2));
+            if (isNaN(pxValue) || pxValue < 1) {
+              throw new Error(`${key} with 'px' format must be a valid number >= 1, value: ${value}`);
+            }
+            // Keep the string value as-is for downstream processing
+          } else {
+            throw new Error(`${key} string value must end with 'px', value: ${value}`);
+          }
+        } else if (typeof value === 'number') {
+          if (value < 1) {
+            throw new Error(`${key} cannot be less than 1, value: ${value}`);
+          }
+        } else {
+          throw new Error(`${key} must be a number or string with 'px' suffix, value: ${value}`);
+        }
+        break;
       case 'minimumContrastRatio':
         value = Math.max(1, Math.min(21, Math.round(value * 10) / 10));
         break;

src/common/services/Services.ts

@@ -231,7 +231,7 @@ export interface ITerminalOptions {
   fontWeightBold?: FontWeight;
   ignoreBracketedPasteMode?: boolean;
   letterSpacing?: number;
-  lineHeight?: number;
+  lineHeight?: number | string;
   linkHandler?: ILinkHandler | null;
   logLevel?: LogLevel;
   logger?: ILogger | null;