Add chord-related method docs to Transpose class (#19)

This commit contains,
* Add js doc for Transpose class methods
* Update unit tests with more tests.
* Update version to 0.3.1.

lib/index.ts

@@ -17,6 +17,13 @@ export class Transpose {
     this.song = song;
   }
 
+  /**
+   * Finds chords in a given line of text.
+   * 
+   * @param line - The line of text to search for chords.
+   * @param offset - The offset of the line within the larger text.
+   * @returns An array of Chord objects containing the chord and its position.
+   */
   private findChords(line: string, offset: number): Chord[] {
     const modifiedLine = line
       .replace(/\||\t|\-|\/|\(|\)|\,|\s/g, " ")
@@ -45,6 +52,12 @@ export class Transpose {
     return chordsWithPositions;
   }
 
+  /**
+   * Parses a string containing chords and returns an array of Chord objects.
+   * 
+   * @param src - The string to be parsed.
+   * @returns An array of Chord objects.
+   */
   private parse(src: string): Chord[] {
     // Parse a text with chords and highlight guitar chords
     const src_textArray = src.split(/\r\n|\r|\n/g);
@@ -60,6 +73,11 @@ export class Transpose {
     return chords;
   }
 
+  /**
+   * Adds HTML tags to highlight chords in the song.
+   * 
+   * @returns The updated song string with chord highlighting tags.
+   */
   getWithTags(): string {
     // Add '<span class="chords-highlighted">...</span>' into the code
     let offset = 0;
@@ -94,6 +112,12 @@ export class Transpose {
     return updatedSong;
   }
 
+  /**
+   * Shifts the scale of the chords by the specified amount.
+   * 
+   * @param shiftBy The amount to shift the scale by. This could be a positive or negative number.
+   * @returns An array of updated chords with the shifted scale.
+   */
   private shiftScale(shiftBy: number): Chord[] {
     let refArrangement: string[] | null = null;
     const updatedChords = this.chords.map((chord) => {
@@ -131,13 +155,25 @@ export class Transpose {
 
     return updatedChords;
   }
-
+
+  /**
+   * Shifts the scale of the chords by the specified amount.
+   * 
+   * @param shiftBy The amount to shift the scale by. This could be either positive or negative number.
+   * @returns The instance of the class with the shifted scale.
+   */
   shiftScaleBy(shiftBy: number): this {
     this.chords = this.shiftScale(shiftBy);
-
     return this;
   }
 
+  /**
+   * Shifts the scale from one chord to another chord.
+   * 
+   * @param from The chord to shift from.
+   * @param to The chord to shift to.
+   * @returns The updated instance of the ChordsTransposer class.
+   */
   shiftScaleFromTo(from: string, to: string): this {
     const arrangement =
       chordsArrangement.indexOf(from) !== -1 &&

package.json

@@ -1,6 +1,6 @@
 {
   "name": "chords-transposer",
-  "version": "0.3.0",
+  "version": "0.3.1",
   "description": "The Chord Transposer is a TypeScript/JavaScript library designed to manipulate and transpose chords within text-based songs.",
   "main": "lib/index.ts",
   "files": [

tests/index.spec.ts

@@ -9,15 +9,6 @@ test("parse test", () => {
   );
 });
 
-test("shiftScaleBy test", () => {
-  const song = "Gm  F    Gm Eb     B   F     B  Gm";
-  const songObj = new Transposer(song);
-
-  expect(songObj.shiftScaleBy(1).getWithTags()).toEqual(
-    '<span class="chords-highlighted">Abm</span>  <span class="chords-highlighted">Gb</span>    <span class="chords-highlighted">Abm</span> <span class="chords-highlighted">E</span>     <span class="chords-highlighted">C</span>   <span class="chords-highlighted">Gb</span>     <span class="chords-highlighted">C</span>  <span class="chords-highlighted">Abm</span>',
-  );
-});
-
 test("shiftScaleFromTo test", () => {
   const song = "Gm  F    Gm Eb     B   F     B  Gm";
 
@@ -42,3 +33,30 @@ test("shiftScaleBy complex test 1", () => {
     '| <span class="chords-highlighted">Bbm</span> | <span class="chords-highlighted">Ab</span> | <span class="chords-highlighted">Bbm</span> | <span class="chords-highlighted">Gb</span> |',
   );
 });
+
+test("shiftScaleBy test", () => {
+  const song = "Gm  F    Gm Eb     B   F     B  Gm";
+  const songObj = new Transposer(song);
+
+  expect(songObj.shiftScaleBy(1).getWithTags()).toEqual(
+    '<span class="chords-highlighted">Abm</span>  <span class="chords-highlighted">Gb</span>    <span class="chords-highlighted">Abm</span> <span class="chords-highlighted">E</span>     <span class="chords-highlighted">C</span>   <span class="chords-highlighted">Gb</span>     <span class="chords-highlighted">C</span>  <span class="chords-highlighted">Abm</span>',
+  );
+});
+
+test("shiftScaleBy test with negative shift", () => {
+  const song = "Gm  F    Gm Eb     B   F     B  Gm";
+  const songObj = new Transposer(song);
+
+  expect(songObj.shiftScaleBy(-1).getWithTags()).toEqual(
+    '<span class=\"chords-highlighted\">Gbm</span>  <span class=\"chords-highlighted\">E</span>    <span class=\"chords-highlighted\">Gbm</span> <span class=\"chords-highlighted\">D</span>     <span class=\"chords-highlighted\">Bb</span>   <span class=\"chords-highlighted\">E</span>     <span class=\"chords-highlighted\">Bb</span>  <span class=\"chords-highlighted\">Gbm</span>',
+  );
+});
+
+test("shiftScaleBy test with zero shift", () => {
+  const song = "Gm  F    Gm Eb     B   F     B  Gm";
+  const songObj = new Transposer(song);
+
+  expect(songObj.shiftScaleBy(0).getWithTags()).toEqual(
+    '<span class="chords-highlighted">Gm</span>  <span class="chords-highlighted">F</span>    <span class="chords-highlighted">Gm</span> <span class="chords-highlighted">Eb</span>     <span class="chords-highlighted">B</span>   <span class="chords-highlighted">F</span>     <span class="chords-highlighted">B</span>  <span class="chords-highlighted">Gm</span>',
+  );
+});