Allow core.scale to be checked by TypeScript compiler

Author: benmccann

src/core/core.scale.js

@@ -228,6 +228,82 @@ function skip(ticks, newTicks, spacing, majorStart, majorEnd) {
 
 class Scale extends Element {
 
+	constructor(cfg) {
+		super();
+
+		/** @type {string} */
+		this.id = cfg.id;
+		this.type = cfg.type;
+		/** @type {object} */
+		this.options = cfg.options;
+		this.ctx = cfg.ctx;
+		this.chart = cfg.chart;
+
+		// implements box
+		/** @type {number | undefined} */
+		this.top = undefined;
+		/** @type {number | undefined} */
+		this.bottom = undefined;
+		/** @type {number | undefined} */
+		this.left = undefined;
+		/** @type {number | undefined} */
+		this.right = undefined;
+		/** @type {number | undefined} */
+		this.width = undefined;
+		/** @type {number | undefined} */
+		this.height = undefined;
+		this.margins = {
+			left: 0,
+			right: 0,
+			top: 0,
+			bottom: 0
+		};
+		// TODO: make maxWidth, maxHeight private
+		/** @type {number | undefined} */
+		this.maxWidth = undefined;
+		/** @type {number | undefined} */
+		this.maxHeight = undefined;
+		/** @type {number | undefined} */
+		this.paddingTop = undefined;
+		/** @type {number | undefined} */
+		this.paddingBottom = undefined;
+		/** @type {number | undefined} */
+		this.paddingLeft = undefined;
+		/** @type {number | undefined} */
+		this.paddingRight = undefined;
+
+		// scale-specific properties
+		/** @type {string | undefined} */
+		this.axis = undefined;
+		/** @type {number | undefined} */
+		this.labelRotation = undefined;
+		this.min = undefined;
+		this.max = undefined;
+		/** @type {object[]} */
+		this.ticks = null;
+		/** @type {object[]} */
+		this._gridLineItems = null;
+		/** @type {object[]} */
+		this._labelItems = null;
+		/** @type {object} */
+		this._labelSizes = null;
+		/** @type {number | undefined} */
+		this._length = undefined;
+		/** @type {object} */
+		this._longestTextCache = {};
+		/** @type {number | undefined} */
+		this._maxLabelLines = undefined;
+		/** @type {number | undefined} */
+		this._startPixel = undefined;
+		/** @type {number | undefined} */
+		this._endPixel = undefined;
+		this._reversePixels = undefined;
+		this._userMax = undefined;
+		this._userMin = undefined;
+		this._ticksLength = undefined;
+		this._borderValue = undefined;
+	}
+
 	/**
 	 * Parse a supported input value to internal representation.
 	 * @param {*} raw
@@ -303,7 +379,7 @@ class Scale extends Element {
 	 * Get the padding needed for the scale
 	 * @method getPadding
 	 * @private
-	 * @returns {Padding} the necessary padding
+	 * @returns {object} the necessary padding
 	 */
 	getPadding() {
 		const me = this;
@@ -357,7 +433,6 @@ class Scale extends Element {
 		me.beforeUpdate();
 
 		// Absorb the master measurements
-		// TODO: make maxWidth, maxHeight private
 		me.maxWidth = maxWidth;
 		me.maxHeight = maxHeight;
 		me.margins = helpers.extend({
@@ -370,7 +445,6 @@ class Scale extends Element {
 		me.ticks = null;
 		me._labelSizes = null;
 		me._maxLabelLines = 0;
-		me._longestTextCache = me._longestTextCache || {};
 		me._gridLineItems = null;
 		me._labelItems = null;
 
@@ -495,7 +569,12 @@ class Scale extends Element {
 	beforeBuildTicks() {
 		helpers.callback(this.options.beforeBuildTicks, [this]);
 	}
-	buildTicks() {}
+	/**
+	 * @return {object[]} the ticks
+	 */
+	buildTicks() {
+		throw new Error('buildTicks must be overriden by a child class');
+	}
 	afterBuildTicks() {
 		helpers.callback(this.options.afterBuildTicks, [this]);
 	}
@@ -804,17 +883,17 @@ class Scale extends Element {
 	 * Returns the location of the given data point. Value can either be an index or a numerical value
 	 * The coordinate (0, 0) is at the upper-left corner of the canvas
 	 * @param value
-	 * @param index
-	 * @param datasetIndex
 	 */
-	getPixelForValue() {}
+	// eslint-disable-next-line no-unused-vars
+	getPixelForValue(value) {}
 
 	/**
 	 * Used to get the data value from a given pixel. This is the inverse of getPixelForValue
 	 * The coordinate (0, 0) is at the upper-left corner of the canvas
 	 * @param pixel
 	 */
-	getValueForPixel() {}
+	// eslint-disable-next-line no-unused-vars
+	getValueForPixel(pixel) {}
 
 	/**
 	 * Returns the location of the tick at the given index
@@ -1063,8 +1142,8 @@ class Scale extends Element {
 			});
 		}
 
-		items.ticksLength = ticksLength;
-		items.borderValue = borderValue;
+		me._ticksLength = ticksLength;
+		me._borderValue = borderValue;
 
 		return items;
 	}
@@ -1209,10 +1288,10 @@ class Scale extends Element {
 			const firstLineWidth = axisWidth;
 			context = {
 				scale: me,
-				tick: me.ticks[items.ticksLength - 1],
+				tick: me.ticks[me._ticksLength - 1],
 			};
-			const lastLineWidth = resolve([gridLines.lineWidth, 1], context, items.ticksLength - 1);
-			const borderValue = items.borderValue;
+			const lastLineWidth = resolve([gridLines.lineWidth, 1], context, me._ticksLength - 1);
+			const borderValue = me._borderValue;
 			let x1, x2, y1, y2;
 
 			if (me.isHorizontal()) {