Add new methods to do datum defaults and validation

src/chart.ts

@@ -13,6 +13,7 @@ import annotations from './helpers/annotations.js'
 import mousetip from './tip.js'
 import helpers from './helpers/index.js'
 import datumDefaults from './datum-defaults.js'
+import datumValidation from './datum-validation.js'
 import globals from './globals.mjs'
 
 export interface ChartMetaMargin {
@@ -156,6 +157,8 @@ export class Chart extends EventEmitter.EventEmitter {
    */
   plot() {
     this.emit('before:plot')
+    this.setDefaultOptions()
+    this.validateOptions()
     this.buildInternalVars()
     this.render()
     this.emit('after:plot')
@@ -182,6 +185,31 @@ export class Chart extends EventEmitter.EventEmitter {
     return cachedInstance
   }
 
+  private setDefaultOptions() {
+    this.options.x = this.options.x || {}
+    this.options.x.type = this.options.x.type || 'linear'
+
+    this.options.y = this.options.y || {}
+    this.options.y.type = this.options.y.type || 'linear'
+
+    for (let d of this.options.data) {
+      datumDefaults(d)
+    }
+  }
+
+  /**
+   * Validate options provides best effort runtime validation of the options.
+   */
+  private validateOptions() {
+    try {
+      for (let datum of this.options.data) {
+        datumValidation(datum)
+      }
+    } catch (e) {
+      throw new Error(`detected invalid options: ${e}`, e)
+    }
+  }
+
   private buildInternalVars() {
     const margin = (this.meta.margin = { left: 40, right: 20, top: 20, bottom: 20 })
     // if there's a title make the top margin bigger
@@ -215,13 +243,7 @@ export class Chart extends EventEmitter.EventEmitter {
       return (self.meta.height * xDiff) / self.meta.width
     }
 
-    this.options.x = this.options.x || {}
-    this.options.x.type = this.options.x.type || 'linear'
-
-    this.options.y = this.options.y || {}
-    this.options.y.type = this.options.y.type || 'linear'
-
-    const xDomain = (this.meta.xDomain = (function (axis: FunctionPlotOptionsAxis) {
+    const xDomain = (function (axis: FunctionPlotOptionsAxis): [number, number] {
       if (axis.domain) {
         return axis.domain
       }
@@ -232,9 +254,10 @@ export class Chart extends EventEmitter.EventEmitter {
         return [1, 10]
       }
       throw Error('axis type ' + axis.type + ' unsupported')
-    })(this.options.x))
+    })(this.options.x)
+    this.meta.xDomain = xDomain
 
-    const yDomain = (this.meta.yDomain = (function (axis: FunctionPlotOptionsAxis) {
+    const yDomain = (function (axis: FunctionPlotOptionsAxis): [number, number] {
       if (axis.domain) {
         return axis.domain
       }
@@ -245,7 +268,8 @@ export class Chart extends EventEmitter.EventEmitter {
         return [1, 10]
       }
       throw Error('axis type ' + axis.type + ' unsupported')
-    })(this.options.y))
+    })(this.options.y)
+    this.meta.yDomain = yDomain
 
     if (!this.meta.xScale) {
       this.meta.xScale = getD3Scale(this.options.x.type)()
@@ -544,7 +568,7 @@ export class Chart extends EventEmitter.EventEmitter {
       .selectAll(':scope > g.graph')
       .data(
         (d: FunctionPlotOptions) => {
-          return d.data.map(datumDefaults)
+          return d.data
         },
         (d: any) => {
           // The key is the function set or other value that uniquely identifies the datum.

src/datum-defaults.ts

@@ -12,9 +12,7 @@ export default function datumDefaults(d: FunctionPlotDatum): FunctionPlotDatum {
     d.sampler = d.graphType !== 'interval' ? 'builtIn' : 'interval'
   }
 
-  // TODO: handle default fnType
-  // default `fnType` is linear
-  if (!('fnType' in d)) {
+  if (!('fnType' in d) && (d.graphType == 'polyline' || d.graphType == 'interval' || d.graphType == 'scatter')) {
     d.fnType = 'linear'
   }
 

src/datum-validation.ts

@@ -0,0 +1,28 @@
+import { FunctionPlotDatum } from './types.js'
+import { assert } from './utils.mjs'
+
+export default function datumValidation(d: FunctionPlotDatum) {
+  validateGraphType(d)
+  validateFnType(d)
+}
+
+function validateGraphType(d: FunctionPlotDatum) {
+  // defaulted to 'interval' in datumDefaults.
+  assert('graphType' in d, `graphType isn't defined`)
+}
+
+function validateFnType(d: FunctionPlotDatum) {
+  const invalid = `invalid option fnType=${d.fnType} with graphType=${d.graphType}`
+  if (d.fnType === 'linear') {
+    assert(d.graphType === 'polyline' || d.graphType === 'interval' || d.graphType === 'scatter', invalid)
+  }
+  if (d.fnType === 'parametric' || d.fnType === 'polar' || d.fnType === 'vector') {
+    assert(d.graphType === 'polyline', invalid)
+  }
+  if (d.fnType === 'points') {
+    assert(d.graphType === 'polyline' || d.graphType === 'scatter', invalid)
+  }
+  if (d.fnType === 'implicit') {
+    assert(d.graphType === 'interval', invalid)
+  }
+}

src/graph-types/interval.ts

@@ -5,6 +5,7 @@ import { infinity, color } from '../utils.mjs'
 
 import { Chart } from '../index.js'
 import { Interval, FunctionPlotDatum, FunctionPlotScale, LinearFunction } from '../types.js'
+import { IntervalSamplerResult } from '../samplers/types.js'
 
 function clampRange(minWidthHeight: number, vLo: number, vHi: number, gLo: number, gHi: number) {
   // issue 69
@@ -83,7 +84,7 @@ export default function interval(chart: Chart) {
       const el = ((plotLine as any).el = d3Select(this))
       const index = d.index
       const closed = d.closed
-      let evaluatedData
+      let evaluatedData: IntervalSamplerResult
       if (d.fnType === 'linear' && typeof (d as LinearFunction).fn === 'string' && d.sampler === 'asyncInterval') {
         evaluatedData = await asyncIntervalEvaluate(chart, d)
       } else {
@@ -92,7 +93,7 @@ export default function interval(chart: Chart) {
       const innerSelection = el.selectAll(':scope > path.line').data(evaluatedData)
 
       // the min height/width of the rects drawn by the path generator
-      const minWidthHeight = Math.max(evaluatedData[0].scaledDx, 1)
+      const minWidthHeight = Math.max((evaluatedData[0] as any).scaledDx, 1)
 
       const cls = `line line-${index}`
       const innerSelectionEnter = innerSelection.enter().append('path').attr('class', cls).attr('fill', 'none')

src/types.ts

@@ -239,7 +239,7 @@ export interface LinearDatum {
   fnType?: 'linear'
 }
 
-export type LinearFunction = LinearDatum & AbstractFunctionDatum
+export type LinearFunction = AbstractFunctionDatum & LinearDatum
 
 export interface ImplicitDatum {
   /**
@@ -250,9 +250,14 @@ export interface ImplicitDatum {
   /**
    */
   fnType: 'implicit'
+
+  /**
+   * The graphType for an implicit function is always 'interval'
+   */
+  graphType: 'interval'
 }
 
-export type ImplicitFunction = ImplicitDatum & AbstractFunctionDatum
+export type ImplicitFunction = AbstractFunctionDatum & ImplicitDatum
 
 export interface PolarDatum {
   /**
@@ -263,7 +268,7 @@ export interface PolarDatum {
   fnType: 'polar'
 }
 
-export type PolarFunction = PolarDatum & AbstractFunctionDatum
+export type PolarFunction = AbstractFunctionDatum & PolarDatum
 
 export interface ParametricDatum {
   /**
@@ -279,7 +284,7 @@ export interface ParametricDatum {
   fnType: 'parametric'
 }
 
-export type ParametricFunction = ParametricDatum & AbstractFunctionDatum
+export type ParametricFunction = AbstractFunctionDatum & ParametricDatum
 
 export interface PointDatum {
   /**
@@ -290,7 +295,7 @@ export interface PointDatum {
   fnType: 'points'
 }
 
-export type PointFunction = PointDatum & AbstractFunctionDatum
+export type PointFunction = AbstractFunctionDatum & PointDatum
 
 export interface VectorDatum {
   /**
@@ -306,7 +311,7 @@ export interface VectorDatum {
   fnType: 'vector'
 }
 
-export type VectorFunction = VectorDatum & AbstractFunctionDatum
+export type VectorFunction = AbstractFunctionDatum & VectorDatum
 
 export interface TextDatum {
   graphType: 'text'
@@ -322,7 +327,7 @@ export interface TextDatum {
   location?: [number, number]
 }
 
-export type TextFunction = TextDatum & AbstractFunctionDatum
+export type TextFunction = AbstractFunctionDatum & TextDatum
 
 export type FunctionPlotDatum =
   | AbstractFunctionDatum

src/utils.mjs

@@ -93,8 +93,17 @@ export function color(data, index) {
 }
 
 /**
- * Infinity is a value that is close to Infinity but not Infinity, it can fit in a JS number.
+ * infinity is a value that is close to Infinity but not Infinity, it can fit in a JS number.
  */
 export function infinity() {
   return 9007199254740991
 }
+
+/**
+ * asserts makes an simple assertion and throws `Error(message)` if the assertion failed
+ */
+export function assert(assertion, message) {
+  if (!assertion) {
+    throw new Error(message)
+  }
+}

test/e2e/graphs.test.ts

@@ -1,4 +1,4 @@
-import puppeteer from 'puppeteer'
+import puppeteer, { Page } from 'puppeteer'
 import { expect, describe, it, beforeAll } from '@jest/globals'
 import { toMatchImageSnapshot } from 'jest-image-snapshot'
 
@@ -12,18 +12,23 @@ const matchSnapshotConfig = {
   failureThresholdType: 'percent'
 }
 
+async function getPage() {
+  const browser = await puppeteer.launch({ headless: 'new' })
+  const page = await browser.newPage()
+  await page.setViewport({
+    width: 1000,
+    height: 1000,
+    deviceScaleFactor: 2
+  })
+  await page.goto('http://localhost:4444/jest-function-plot.html')
+  return page
+}
+
 describe('Function Plot', () => {
-  async function getPage() {
-    const browser = await puppeteer.launch({ headless: 'new' })
-    const page = await browser.newPage()
-    await page.setViewport({
-      width: 1000,
-      height: 1000,
-      deviceScaleFactor: 2
-    })
-    await page.goto('http://localhost:4444/jest-function-plot.html')
-    return page
-  }
+  let page: Page
+  beforeAll(async function () {
+    page = await getPage()
+  })
 
   function stripWrappingFunction(fnString: string) {
     fnString = fnString.replace(/^\s*function\s*\(\)\s*\{/, '')
@@ -33,7 +38,6 @@ describe('Function Plot', () => {
 
   snippets.forEach((snippet) => {
     it(snippet.testName, async () => {
-      const page = await getPage()
       await page.evaluate(stripWrappingFunction(snippet.fn.toString()))
       // When a function that's evaluated asynchronously runs
       // it's possible that the rendering didn't happen yet.
@@ -52,7 +56,6 @@ describe('Function Plot', () => {
   })
 
   it('update the graph using multiple renders', async () => {
-    const page = await getPage()
     const firstRender = `
       const dualRender = {
         target: '#playground',