feat: add lineMode option to parser for flexible line formatting (#7)

Author: cheton

README.md

@@ -80,7 +80,7 @@ parser.parseFile('example.nc', function(err, results) {
 ### batchSize
 
 Type: `Number`
-Default: `1000`
+Default: 1000
 
 The batch size.
 
@@ -99,16 +99,27 @@ parser.parseLine('G0 X0 Y0', { flatten: true });
 // => { line: 'G0 X0 Y0', words: [ 'G0', 'X0', 'Y0' ] }
 ```
 
-### noParseLine
+### lineMode
 
-Type: `Boolean`
-Default: `false`
+Type: `String`  
+Default: `'original'`
 
-True to not parse line, false otherwise.
+The `lineMode` option specifies how the parsed line should be formatted. The following values are supported:
+- `'original'`: Keeps the line unchanged, including comments and whitespace. (Default)
+- `'minimal'`: Removes comments, trims leading and trailing whitespace, but preserves inner whitespace.
+- `'compact'`: Removes both comments and all whitespace.
+
+Example usage:
 
 ```js
-parser.parseFile('/path/to/file', { noParseLine: true }, function(err, results) {
-});
+parser.parseLine('G0 X0 Y0 ; comment', { lineMode: 'original' });
+// => { line: 'G0 X0 Y0 ; comment', words: [ [ 'G', 0 ], [ 'X', 0 ], [ 'Y', 0 ] ] }
+
+parser.parseLine('G0 X0 Y0 ; comment', { lineMode: 'minimal' });
+// => { line: 'G0 X0 Y0', words: [ [ 'G', 0 ], [ 'X', 0 ], [ 'Y', 0 ] ] }
+
+parser.parseLine('G0 X0 Y0 ; comment', { lineMode: 'compact' });
+// => { line: 'G0X0Y0', words: [ [ 'G', 0 ], [ 'X', 0 ], [ 'Y', 0 ] ] }
 ```
 
 ## G-code Interpreter

src/__tests__/index.test.js

@@ -43,44 +43,48 @@ describe('Pass an empty text as the first argument', () => {
   });
 });
 
-describe('Contains only lines', () => {
-  it('should not parse G-code commands.', (done) => {
-    const filepath = path.resolve(__dirname, 'fixtures/circle.gcode');
-    parseFile(filepath, { noParseLine: true }, (err, results) => {
-      expect(results.length).toBe(7);
-      done();
-    })
-      .on('data', (data) => {
-        expect(typeof data).toBe('object');
-        expect(typeof data.line).toBe('string');
-        expect(data.words).toBe(undefined);
-      })
-      .on('end', (results) => {
-        expect(results.length).toBe(7);
-      });
-  });
-});
-
 describe('Invalid G-code words', () => {
-  it('should ignore invalid g-code words', (done) => {
+  it('should ignore invalid g-code words', () => {
     const data = parseLine('messed up');
     expect(typeof data).toBe('object');
     expect(data.line).toBe('messed up');
     expect(data.words).toHaveLength(0);
-    done();
+  });
+});
+
+describe('Using the `lineMode` option', () => {
+  it('should return the original line with comments and whitespace in original mode', () => {
+    const line = 'M6 (tool change;) T1 ; comment';
+    const result = parseLine(line, { lineMode: 'original' });
+    expect(result.line).toBe('M6 (tool change;) T1 ; comment');
+    expect(result.words).toEqual([['M', 6], ['T', 1]]);
+  });
+
+  it('should return the line without comments but with whitespace in minimal mode', () => {
+    const line = 'M6 (tool change;) T1 ; comment';
+    const result = parseLine(line, { lineMode: 'minimal' });
+    expect(result.line).toBe('M6  T1');
+    expect(result.words).toEqual([['M', 6], ['T', 1]]);
+  });
+
+  it('should return the line without comments and whitespace in compact mode', () => {
+    const line = 'M6 (tool change;) T1 ; comment';
+    const result = parseLine(line, { lineMode: 'compact' });
+    expect(result.line).toBe('M6T1');
+    expect(result.words).toEqual([['M', 6], ['T', 1]]);
   });
 });
 
 describe('Commands', () => {
-  it('should be able to parse $ command (e.g. Grbl).', (done) => {
+  it('should be able to parse $ command (e.g. Grbl).', () => {
     const data = parseLine('$H $C');
     expect(typeof data).toBe('object');
     expect(typeof data.line).toBe('string');
     expect(data.words).toHaveLength(0);
     expect(data.cmds).toEqual(['$H', '$C']);
-    done();
   });
-  it('should be able to parse JSON command (e.g. TinyG, g2core).', (done) => {
+
+  it('should be able to parse JSON command (e.g. TinyG, g2core).', () => {
     { // {sr:{spe:t,spd,sps:t}}
       const data = parseLine('{sr:{spe:t,spd:t,sps:t}}');
       expect(typeof data).toBe('object');
@@ -95,10 +99,9 @@ describe('Commands', () => {
       expect(data.words).toHaveLength(0);
       expect(data.cmds).toEqual(['{mt:n}']);
     }
-
-    done();
   });
-  it('should be able to parse % command (e.g. bCNC, CNCjs).', (done) => {
+
+  it('should be able to parse % command (e.g. bCNC, CNCjs).', () => {
     { // %wait
       const data = parseLine('%wait');
       expect(typeof data).toBe('object');
@@ -138,8 +141,6 @@ describe('Commands', () => {
       expect(data.words).toHaveLength(0);
       expect(data.cmds).toEqual(['%x0=posx,y0=posy,z0=posz']);
     }
-
-    done();
   });
 });
 
@@ -323,7 +324,7 @@ describe('Event listeners', () => {
 });
 
 describe('parseLine()', () => {
-  it('should return expected results.', (done) => {
+  it('should return expected results.', () => {
     expect(parseLine('G0 X0 Y0')).toEqual({
       line: 'G0 X0 Y0',
       words: [['G', 0], ['X', 0], ['Y', 0]]
@@ -332,7 +333,6 @@ describe('parseLine()', () => {
       line: 'G0 X0 Y0',
       words: ['G0', 'X0', 'Y0']
     });
-    done();
   });
 });
 
@@ -452,12 +452,11 @@ describe('parseStringSync()', () => {
     }
   ];
 
-  it('should return expected results.', (done) => {
+  it('should return expected results.', () => {
     const filepath = path.resolve(__dirname, 'fixtures/circle.gcode');
     const str = fs.readFileSync(filepath, 'utf8');
     const results = parseStringSync(str);
     expect(results).toEqual(expectedResults);
-    done();
   });
 });
 

src/index.js

@@ -66,53 +66,71 @@ const parseLine = (() => {
   };
   // http://linuxcnc.org/docs/html/gcode/overview.html#gcode:comments
   // Comments can be embedded in a line using parentheses () or for the remainder of a lineusing a semi-colon. The semi-colon is not treated as the start of a comment when enclosed in parentheses.
-  const stripAndExtractComments = (() => {
+  const stripComments = (() => {
     // eslint-disable-next-line no-useless-escape
     const re1 = new RegExp(/\(([^\)]*)\)/g); // Match anything inside parentheses
     const re2 = new RegExp(/;(.*)$/g); // Match anything after a semi-colon to the end of the line
-    const re3 = new RegExp(/\s+/g);
 
     return (line) => {
       const comments = [];
       // Extract comments from parentheses
       line = line.replace(re1, (match, p1) => {
-        const strippedLine = p1.trim();
-        comments.push(strippedLine); // Add the match to comments
+        const lineWithoutComments = p1.trim();
+        comments.push(lineWithoutComments); // Add the match to comments
         return '';
       });
       // Extract comments after a semi-colon
       line = line.replace(re2, (match, p1) => {
-        const strippedLine = p1.trim();
-        comments.push(strippedLine); // Add the match to comments
+        const lineWithoutComments = p1.trim();
+        comments.push(lineWithoutComments); // Add the match to comments
         return '';
       });
-      // Remove whitespace characters
-      line = line.replace(re3, '');
+      line = line.trim();
       return [line, comments];
     };
   })();
+
+  const stripWhitespace = (line) => {
+    // Remove whitespace characters
+    const re = new RegExp(/\s+/g);
+    return line.replace(re, '');
+  };
+
   // eslint-disable-next-line no-useless-escape
   const re = /(%.*)|({.*)|((?:\$\$)|(?:\$[a-zA-Z0-9#]*))|([a-zA-Z][0-9\+\-\.]+)|(\*[0-9]+)/igm;
 
-  return (line, options) => {
-    options = options || {};
-    options.flatten = !!options.flatten;
-    options.noParseLine = !!options.noParseLine;
-
-    const result = {
-      line: line
-    };
+  return (line, options = {}) => {
+    options.flatten = !!options?.flatten;
 
-    if (options.noParseLine) {
-      return result;
+    const validLineModes = [
+      'original', // Keeps the line unchanged, including comments and whitespace. (Default)
+      'minimal',  // Removes comments, trims leading and trailing whitespace, but preserves inner whitespace.
+      'compact',  // Removes both comments and all whitespace.
+    ];
+    if (!validLineModes.includes(options?.lineMode)) {
+      options.lineMode = validLineModes[0];
     }
 
-    result.words = [];
+    const result = {
+      line: '',
+      words: [],
+    };
 
     let ln; // Line number
     let cs; // Checksum
-    const [strippedLine, comments] = stripAndExtractComments(line);
-    const words = strippedLine.match(re) || [];
+    const originalLine = line;
+    const [minimalLine, comments] = stripComments(line);
+    const compactLine = stripWhitespace(minimalLine);
+
+    if (options.lineMode === 'compact') {
+      result.line = compactLine;
+    } else if (options.lineMode === 'minimal') {
+      result.line = minimalLine;
+    } else {
+      result.line = originalLine;
+    }
+
+    const words = compactLine.match(re) || [];
 
     if (comments.length > 0) {
       result.comments = comments;
@@ -243,7 +261,7 @@ const parseString = (str, options, callback = noop) => {
 };
 
 const parseStringSync = (str, options) => {
-  const { flatten = false, noParseLine = false } = { ...options };
+  const { flatten = false } = { ...options };
   const results = [];
   const lines = str.split('\n');
 
@@ -254,7 +272,6 @@ const parseStringSync = (str, options) => {
     }
     const result = parseLine(line, {
       flatten,
-      noParseLine
     });
     results.push(result);
   }
@@ -272,7 +289,6 @@ class GCodeLineStream extends Transform {
 
   options = {
     batchSize: 1000,
-    noParseLine: false
   };
 
   lineBuffer = '';
@@ -282,7 +298,6 @@ class GCodeLineStream extends Transform {
   // @param {object} [options] The options object
   // @param {number} [options.batchSize] The batch size.
   // @param {boolean} [options.flatten] True to flatten the array, false otherwise.
-  // @param {boolean} [options.noParseLine] True to not parse line, false otherwise.
   constructor(options = {}) {
     super({ objectMode: true });
 
@@ -336,7 +351,6 @@ class GCodeLineStream extends Transform {
       if (line.length > 0) {
         const result = parseLine(line, {
           flatten: this.options.flatten,
-          noParseLine: this.options.noParseLine
         });
         this.push(result);
       }
@@ -349,7 +363,6 @@ class GCodeLineStream extends Transform {
       if (line.length > 0) {
         const result = parseLine(line, {
           flatten: this.options.flatten,
-          noParseLine: this.options.noParseLine
         });
         this.push(result);
       }