solving strip comments

Author: nerdrun

strip_comments/main.js

@@ -0,0 +1,34 @@
+function solution(text, markers) {
+  if(!isMarker(text, markers)) return text;
+  const array = text.split('');
+  let result = '';
+
+  for(let i = 0; i < array.length; i++) {
+    if(isMarker(array[i], markers)) {
+      result = trimEnd(result);
+      const lineBreakIndex = findNextLineBreak(array.slice(i));
+      if(lineBreakIndex === -1) {
+        array.splice(i, (array.length - 1) - i);
+      } else {
+        array.splice(i, lineBreakIndex - 1);
+      }
+    } else {
+      result += array[i];
+    }
+  }
+  return trimEnd(result);
+}
+
+function isMarker(text, markers) {
+  return markers.includes(text);
+}
+
+function trimEnd(text) {
+  return text.lastIndexOf(' ') === text.length - 1 ? text.trimEnd() : text;
+}
+
+function findNextLineBreak(text) {
+  return text.indexOf('\n');
+}
+
+module.exports = { solution, isMarker, findNextLineBreak };

strip_comments/main.test.js

@@ -0,0 +1,99 @@
+const { isMarker, findNextLineBreak, solution } = require('./main');
+
+describe('Check marker test', () => {
+  test('a is not a marker of #', () => {
+    expect(isMarker('a', ['#'])).toBe(false);
+  });
+
+  test('# is a marker of #', () => {
+    expect(isMarker('#', ['#'])).toBe(true);
+  });
+
+  test('b is a not marker of #,!', () => {
+    expect(isMarker('b', ['#', '!'])).toBe(false);
+  });
+
+  test('! is a marker of #,!', () => {
+    expect(isMarker('!', ['#', '!'])).toBe(true);
+  });
+});
+
+describe('find the next index of \n', () => {
+  test('the next index of abc\n is 3', () => {
+    expect(findNextLineBreak('abc\n')).toBe(3);
+  });
+
+  test('the next index of abc is -1', () => {
+    expect(findNextLineBreak('abc')).toBe(-1);
+  });
+
+  test('the next index of abcde\nabcde\n is 5', () => {
+    expect(findNextLineBreak('abcde\nabcde\n')).toBe(5);
+  });
+});
+
+describe('Strip comments', () => {
+  test('a returns a', () => {
+    expect(solution('a', ['#'])).toBe('a');
+  });
+
+  test('\n returns \n', () => {
+    expect(solution('\n', ['#'])).toBe('\n');
+  });
+
+  test('a\n returns a\n', () => {
+    expect(solution('a\n', ['#'])).toBe('a\n');
+  });
+
+  test('a# returns a', () => {
+    expect(solution('a#', ['#'])).toBe('a');
+  });
+
+  test('a#hello returns a', () => {
+    expect(solution('a#hello', ['#'])).toBe('a');
+  });
+
+  test('#hello returns ', () => {
+    expect(solution('#hello', ['#'])).toBe('');
+  });
+
+  test('a#hello\nh returns a\nh', () => {
+    expect(solution('a#hello\nh', ['#'])).toBe('a\nh');
+  });
+
+  test('a#hello\nhello\n#hi returns ahello', () => {
+    expect(solution('a#hello\nhello\n#hi', ['#'])).toBe('a\nhello\n');
+  });
+
+  test('aa bb cc   returns ahello', () => {
+    expect(solution('aa bb cc  ', ['#'])).toBe('aa bb cc');
+  });
+
+  test('aa bb # cc returns aa bb', () => {
+    expect(solution('aa bb # cc', ['#'])).toBe('aa bb');
+  });
+
+  test('aa# bb cc returns aa', () => {
+    expect(solution('aa# bb cc', ['#'])).toBe('aa');
+  });
+
+  test('aa # bb\ncc dd return aa\ncc dd', () => {
+    expect(solution('aa # bb\ncc dd', ['#'])).toBe('aa\ncc dd');
+  });
+
+  test('no markers return the original text', () => {
+    expect(solution('aa # bb # cc', [])).toBe('aa # bb # cc');
+  });
+
+  test('apples, pears # and bananas\n returns apples, pears\n', () => {
+    expect(solution('apples, pears # and bananas\n', ['#','!'])).toBe('apples, pears\n');
+  });
+
+  test('aa # bb # cc returns aa', () => {
+    expect(solution('aa # bb # cc', ['#','!'])).toBe('aa');
+  });
+
+  test('apples, pears # and bananas\ngrapes\nbananas !apples returns apples, pears\ngrapes\nbananas', () => {
+    expect(solution('apples, pears # and bananas\ngrapes\nbananas !apples', ['#','!'])).toBe('apples, pears\ngrapes\nbananas');
+  });
+});