feat(2018 day-13): parse, store, and display track with carts

Author: developher-net

2018/day-13/solution.js

@@ -0,0 +1,16 @@
+const {
+  Track
+} = require('./tracks')
+
+/* eslint-disable */
+const data = `/->-\\
+|   |  /----\\
+| /-+--+-\\  |
+| | |  | v  |
+\\-+-/  \\-+--/
+  \\------/   `
+/* eslint-enable */
+
+const mytrack = new Track(data)
+const actual = mytrack.display()
+console.log(actual)

2018/day-13/tracks.js

@@ -0,0 +1,68 @@
+class Track {
+  constructor (track) {
+    this.layout = []
+    this.carts = []
+    this.cartDirections = ['^', '>', 'v', '<']
+    this.frame = 0
+    this.setLayout(track)
+  }
+
+  setLayout (track) {
+    this.layout = track.split('\n')
+    this.layout = this.layout.map((e) => { return e.split('') })
+    this.extractCarts()
+  }
+
+  /**
+   * Locates carts on the imported layout and pops them out to the carts list
+   */
+  extractCarts () {
+    this.layout = this.layout.map((y, idy) => {
+      return y.map((x, idx) => {
+        // Pop the cart into the cart list with its location
+        if (this.cartDirections.indexOf(x) >= 0) {
+          this.carts.push({
+            x: idx,
+            y: idy,
+            direction: x
+          })
+          // Replace the cart on the track with a track segment
+          // (Assuming cart initial states aren't on instersections)
+          x = (this.cartDirections.indexOf(x) % 2 === 0) ? '|' : '-'
+        }
+        return x
+      })
+    })
+  }
+
+  /**
+   * Gets the track segment at the specified coordinates
+   * @param {*} x Number
+   * @param {*} y Number
+   */
+  getSegmentType (x, y) {
+    return this.layout[y][x]
+  }
+
+  /**
+   * Displays the current state of the track
+   */
+  display () {
+    let output = ''
+    const layout = JSON.parse(JSON.stringify(this.layout)) // Deep copy
+    // Include the carts
+    this.carts.forEach((cart) => {
+      layout[cart.y][cart.x] = cart.direction
+    })
+    layout.forEach((y) => {
+      output += y.join('')
+      output += '\n'
+    })
+
+    return output.trim()
+  }
+}
+
+module.exports = {
+  Track
+}

2018/day-13/tracks.test.js

@@ -0,0 +1,56 @@
+/* eslint-env mocha */
+const expect = require('chai').expect
+const {
+  Track
+} = require('./tracks')
+
+const data = `/->-\\
+|   |  /----\\
+| /-+--+-\\  |
+| | |  | v  |
+\\-+-/  \\-+--/
+  \\------/   `.trim()
+
+describe('--- Day 13: Mine Cart Madness ---', () => {
+  describe('Part 1:', () => {
+    describe('new Track(layout)', () => {
+      it('Initializes a new track with layout', () => {
+        const track = new Track(data)
+        expect(track.layout[4][12]).to.equal('/')
+      })
+      it('splits out and stores the carts as addressable data', () => {
+        const expected = [{
+          x: 2,
+          y: 0,
+          direction: '>'
+        }, {
+          x: 9,
+          y: 3,
+          direction: 'v'
+        }]
+        const track = new Track(data)
+        const actual = track.carts
+        expect(actual).to.deep.equal(expected)
+      })
+    })
+    describe('advance()', () => {
+      it.skip('iterates the state of the track')
+    })
+    describe('display()', () => {
+      it('renders the current track state', () => {
+        const expected = data
+        const track = new Track(data)
+        const actual = track.display()
+        expect(actual).to.equal(expected)
+      })
+    })
+    describe('getSegmentType(x,y)', () => {
+      it.skip('queries the type of segment at location x,y', () => {
+        const expected = '-'
+        const track = new Track(data)
+        const actual = track.getSegmentType(5, 2)
+        expect(actual).to.equal(expected)
+      })
+    })
+  })
+})