feat(text): append, appendLine, appendLines

README.md

@@ -46,6 +46,7 @@ Work with text files using the `withFile` function. It opens the file, passes th
 ```ts
 await withFile('example.txt', (f) => {
   f.replaceAll('old', 'new');
+  f.appendLine('footer');
   f.insertLine('fizz', { aboveEvery: 'buzz' });
   f.deleteLine('bye');
 });

src/text.ts

@@ -225,4 +225,36 @@ export class Text {
     });
     this.content = lines.join('\n');
   }
+
+  /**
+   * Appends `text` to the end of the text.
+   *
+   * @param text The text to append.
+   */
+  append(text: string) {
+    this.content += text;
+  }
+
+  /**
+   * Appends a line to the end of the text.
+   *
+   * @param line The text to append.
+   */
+  appendLine(line: string) {
+    if (!this.content.endsWith('\n')) {
+      this.content += '\n';
+    }
+    this.content += `${line}\n`;
+  }
+
+  /**
+   * Appends lines to the end of the text.
+   *
+   * @param lines Array of lines to append.
+   */
+  appendLines(lines: string[]) {
+    if (lines.length > 0) {
+      this.appendLine(lines.join('\n'));
+    }
+  }
 }

tests/text.spec.ts

@@ -254,4 +254,52 @@ describe('Text', () => {
       expect(text.content).to.equal('one\ntwo');
     });
   });
+
+  describe('append', () => {
+    it('should append the text', () => {
+      const text = new Text('one\n');
+      text.append('two');
+      expect(text.content).to.equal('one\ntwo');
+    });
+
+    it('should not start a new line', () => {
+      const text = new Text('one\ntwo');
+      text.append('three');
+      expect(text.content).to.equal('one\ntwothree');
+    });
+  });
+
+  describe('appendLine', () => {
+    it('should append the line with a line ending', () => {
+      const text = new Text('one\n');
+      text.appendLine('two');
+      expect(text.content).to.equal('one\ntwo\n');
+    });
+
+    it('should add a line ending to the previous line if required', () => {
+      const text = new Text('one');
+      text.appendLine('two');
+      expect(text.content).to.equal('one\ntwo\n');
+    });
+
+    it('should not prevent explicitly adding extra linebreaks', () => {
+      const text = new Text('one\n');
+      text.appendLine('\ntwo\n');
+      expect(text.content).to.equal('one\n\ntwo\n\n');
+    });
+  });
+
+  describe('appendLines', () => {
+    it('should append the lines with line endings', () => {
+      const text = new Text('one\n');
+      text.appendLines(['two', 'three']);
+      expect(text.content).to.equal('one\ntwo\nthree\n');
+    });
+
+    it('should add a line ending to the previous line if required', () => {
+      const text = new Text('one');
+      text.appendLines(['two', 'three']);
+      expect(text.content).to.equal('one\ntwo\nthree\n');
+    });
+  });
 });