adopt vitest; substitute images if they approximately match the expected images

Fil · Fil · commit b65a29801ec2 · 2026-03-11T15:36:46.000+01:00
diff --git a/package.json b/package.json
@@ -27,9 +27,9 @@
     "src/**/*.js"
   ],
   "scripts": {
-    "test": "yarn test:mocha && yarn test:tsc && yarn test:lint && yarn test:prettier",
-    "test:coverage": "c8 yarn test:mocha",
-    "test:mocha": "mkdir -p test/output && TZ=America/Los_Angeles tsx node_modules/.bin/mocha 'test/**/*-test.*' 'test/plot.*'",
+    "test": "yarn test:vitest && yarn test:tsc && yarn test:lint && yarn test:prettier",
+    "test:coverage": "TZ=America/Los_Angeles vitest run --coverage",
+    "test:vitest": "TZ=America/Los_Angeles vitest run",
     "test:lint": "eslint src test",
     "test:prettier": "prettier --check src test",
     "test:tsc": "tsc",
@@ -52,12 +52,11 @@
     "@rollup/plugin-node-resolve": "^16.0.0",
     "@rollup/plugin-terser": "^0.4.0",
     "@types/d3": "^7.4.0",
-    "@types/mocha": "^10.0.1",
     "@types/node": "^22.13.2",
     "@typescript-eslint/eslint-plugin": "^8.24.0",
     "@typescript-eslint/parser": "^8.24.0",
+    "@vitest/coverage-v8": "^4.0.18",
     "apache-arrow": "^19.0.0",
-    "c8": "^10.1.3",
     "canvas": "^3.1.0",
     "d3-geo-projection": "^4.0.0",
     "eslint": "^9.20.1",
@@ -67,25 +66,14 @@
     "js-beautify": "1",
     "jsdom": "^26.0.0",
     "markdown-it-container": "^4.0.0",
-    "mocha": "^11.1.0",
     "prettier": "~3.0.0",
     "rollup": "^4.9.1",
     "topojson-client": "^3.1.0",
     "ts-morph": "^25.0.1",
-    "tsx": "^4.7.0",
     "typescript": "^5.0.2",
     "vite": "^6.1.0",
-    "vitepress": "^1.3.1"
-  },
-  "c8": {
-    "all": true,
-    "include": [
-      "src/**/*.js"
-    ],
-    "reporter": [
-      "text",
-      "lcov"
-    ]
+    "vitepress": "^1.3.1",
+    "vitest": "^4.0.8"
   },
   "dependencies": {
     "d3": "^7.9.0",
diff --git a/test/assert.js b/test/assert.js
@@ -1,4 +1,4 @@
-import assert from "assert";
+import {assert} from "vitest";
 
 function warns(run, expected = /warning/i) {
   const actual = [];
diff --git a/test/docs-test.js b/test/docs-test.js
@@ -1,4 +1,4 @@
-import assert from "assert";
+import {assert, it} from "vitest";
 import {readMarkdownFiles, readMarkdownSource, getAnchors, getLinks} from "../docs/components/links.js";
 
 it("documentation links point to existing internal anchors", async () => {
diff --git a/test/document-test.js b/test/document-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 import {JSDOM} from "jsdom";
 
 it("Plot.plot supports the document option", () => {
diff --git a/test/event-test.js b/test/event-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import * as assert from "assert";
 import {JSDOM} from "jsdom";
 
 it("Plot uses the context’s event", () => {
diff --git a/test/facet-test.js b/test/facet-test.js
@@ -1,7 +1,7 @@
 import * as Plot from "@observablehq/plot";
 import * as d3 from "d3";
 import assert from "./assert.js";
-import it from "./jsdom.js";
+import {it} from "vitest";
 
 it("mark data parallel to facet data triggers a warning", async () => {
   const data = await d3.csv("data/anscombe.csv", d3.autoType);
diff --git a/test/interval-test.js b/test/interval-test.js
@@ -1,4 +1,4 @@
-import assert from "assert";
+import {assert, describe, it} from "vitest";
 import {numberInterval} from "../src/options.js";
 
 describe("numberInterval(interval)", () => {
diff --git a/test/jsdom.js b/test/jsdom.js
diff --git a/test/legend-test.js b/test/legend-test.js
@@ -1,6 +1,5 @@
 import * as Plot from "@observablehq/plot";
-import * as assert from "assert";
-import it from "./jsdom.js";
+import {assert, it} from "vitest";
 
 it(`Plot.legend({color: {type: "identity"}}) returns undefined`, () => {
   assert.strictEqual(Plot.legend({color: {type: "identity"}}), undefined);
diff --git a/test/mark-test.ts b/test/mark-test.ts
@@ -1,17 +1,16 @@
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
-import it from "./jsdom.js";
+import {assert, it} from "vitest";
 
 it("mark(data, {sort}) needs y1 and y2 when sorting by height", () => {
-  assert.throws(() => Plot.dot([], {sort: {x: "height"}}).plot(), /^Error: missing channel: y1$/);
-  assert.throws(() => Plot.dot([], {channels: {y1: "1"}, sort: {x: "height"}}).plot(), /^Error: missing channel: y2$/);
+  assert.throws(() => Plot.dot([], {sort: {x: "height"}}).plot(), /missing channel: y1$/);
+  assert.throws(() => Plot.dot([], {channels: {y1: "1"}, sort: {x: "height"}}).plot(), /missing channel: y2$/);
 });
 
 it("mark(data, {sort}) needs x1 and x2 when sorting by width", () => {
-  assert.throws(() => Plot.dot([], {sort: {y: "width"}}).plot(), /^Error: missing channel: x1$/);
-  assert.throws(() => Plot.dot([], {channels: {x1: "1"}, sort: {y: "width"}}).plot(), /^Error: missing channel: x2$/);
+  assert.throws(() => Plot.dot([], {sort: {y: "width"}}).plot(), /missing channel: x1$/);
+  assert.throws(() => Plot.dot([], {channels: {x1: "1"}, sort: {y: "width"}}).plot(), /missing channel: x2$/);
 });
 
 it("mark(data, {sort}) rejects an invalid order", () => {
-  assert.throws(() => Plot.dotY([0, 1], {sort: {y: {value: "x", order: "neo" as any}}}).plot(), /^Error: invalid order: neo$/); // prettier-ignore
+  assert.throws(() => Plot.dotY([0, 1], {sort: {y: {value: "x", order: "neo" as any}}}).plot(), /invalid order: neo$/); // prettier-ignore
 });
diff --git a/test/marks/area-test.js b/test/marks/area-test.js
@@ -1,6 +1,6 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
 import {curveLinear, curveStep} from "d3";
-import assert from "assert";
 
 it("area(data, options) has the expected defaults", () => {
   const area = Plot.area(undefined, {x1: "0", y1: "1"});
diff --git a/test/marks/auto-test.js b/test/marks/auto-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("Plot.autoSpec makes a histogram from a quantitative dimension", () => {
   const data = [{value: 1}, {value: 1}, {value: 38}];
diff --git a/test/marks/bar-test.js b/test/marks/bar-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("barX() has the expected defaults", () => {
   const bar = Plot.barX();
diff --git a/test/marks/cell-test.js b/test/marks/cell-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("cell() has the expected defaults", () => {
   const cell = Plot.cell();
diff --git a/test/marks/dot-test.js b/test/marks/dot-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("dot() has the expected defaults", () => {
   const dot = Plot.dot();
diff --git a/test/marks/format-test.js b/test/marks/format-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("formatNumber(locale) does the right thing", () => {
   assert.strictEqual(Plot.formatNumber()(Math.PI), "3.142");
diff --git a/test/marks/frame-test.js b/test/marks/frame-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("frame(options) has the expected defaults", () => {
   const frame = Plot.frame();
diff --git a/test/marks/image-test.js b/test/marks/image-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("image(undefined, {src}) has the expected defaults", () => {
   const image = Plot.image(undefined, {src: "foo"});
diff --git a/test/marks/line-test.js b/test/marks/line-test.js
@@ -1,7 +1,7 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
 import {curveStep} from "d3";
 import {curveAuto} from "../../src/curve.js";
-import assert from "assert";
 
 it("line() has the expected defaults", () => {
   const line = Plot.line();
@@ -117,8 +117,8 @@ it("line(data, {curve}) specifies a named curve or function", () => {
 });
 
 it("line(data, {curve}) rejects an invalid curve", () => {
-  assert.throws(() => Plot.lineY([], {y: 1, curve: "neo"}), /^Error: unknown curve: neo$/);
-  assert.throws(() => Plot.lineY([], {y: 1, curve: 42}), /^Error: unknown curve: 42$/);
+  assert.throws(() => Plot.lineY([], {y: 1, curve: "neo"}), /unknown curve: neo$/);
+  assert.throws(() => Plot.lineY([], {y: 1, curve: 42}), /unknown curve: 42$/);
 });
 
 it("line(data, {curve}) accepts the explicit auto curve", () => {
diff --git a/test/marks/link-test.js b/test/marks/link-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("link(data, options) has the expected defaults", () => {
   const link = Plot.link(undefined, {x1: "0", y1: "1", x2: "2", y2: "3"});
diff --git a/test/marks/memoize-test.js b/test/marks/memoize-test.js
@@ -1,5 +1,5 @@
+import {assert, describe, it} from "vitest";
 import {memoize1} from "../../src/memoize.js";
-import assert from "assert";
 
 describe("memoize1(compute)", () => {
   it("returns the cached value with repeated calls", () => {
diff --git a/test/marks/rect-test.js b/test/marks/rect-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("rect(data, options) has the expected defaults", () => {
   const rect = Plot.rect(undefined, {x1: "0", y1: "1", x2: "2", y2: "3"});
diff --git a/test/marks/rule-test.js b/test/marks/rule-test.js
@@ -1,6 +1,5 @@
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
-import it from "../jsdom.js";
+import {assert, it} from "vitest";
 
 it("ruleX() has the expected defaults", () => {
   const rule = Plot.ruleX();
diff --git a/test/marks/text-test.js b/test/marks/text-test.js
@@ -1,6 +1,6 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
 import {clipEnd, clipMiddle, clipStart, defaultWidth, readCharacter} from "../../src/marks/text.js";
-import assert from "assert";
 
 it("text() has the expected defaults", () => {
   const text = Plot.text();
diff --git a/test/marks/tick-test.js b/test/marks/tick-test.js
@@ -1,5 +1,5 @@
+import {assert, it} from "vitest";
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
 
 it("tickX() has the expected defaults", () => {
   const tick = Plot.tickX();
diff --git a/test/marks/time-test.js b/test/marks/time-test.js
@@ -1,4 +1,4 @@
-import assert from "assert";
+import {assert, it} from "vitest";
 import * as d3 from "d3";
 import {timeInterval, utcInterval} from "../../src/time.js";
 
diff --git a/test/options-d-test.ts b/test/options-d-test.ts
@@ -1,5 +1,8 @@
+import {it} from "vitest";
 import {valueof} from "../src/options.js";
 
+it.skip("type-only tests, checked by tsc", () => {});
+
 // A function is not a valid input data
 // eslint-disable-next-line @typescript-eslint/ban-ts-comment
 // @ts-expect-error
diff --git a/test/options-test.js b/test/options-test.js
@@ -1,4 +1,4 @@
-import assert from "assert";
+import {assert, it} from "vitest";
 import {identity, isNumericString, valueof} from "../src/options.js";
 
 it("isNumericString detects numeric strings", () => {
diff --git a/test/plot-test.ts b/test/plot-test.ts
@@ -1,8 +1,7 @@
 import * as Plot from "@observablehq/plot";
-import assert from "assert";
-import it from "./jsdom.js";
+import {assert, it} from "vitest";
 
 it("plot({aspectRatio}) rejects unsupported scale types", () => {
-  assert.throws(() => Plot.dot([]).plot({aspectRatio: true, x: {type: "symlog"}}), /^Error: unsupported x scale for aspectRatio: symlog$/); // prettier-ignore
-  assert.throws(() => Plot.dot([]).plot({aspectRatio: true, y: {type: "symlog"}}), /^Error: unsupported y scale for aspectRatio: symlog$/); // prettier-ignore
+  assert.throws(() => Plot.dot([]).plot({aspectRatio: true, x: {type: "symlog"}}), /unsupported x scale for aspectRatio: symlog$/); // prettier-ignore
+  assert.throws(() => Plot.dot([]).plot({aspectRatio: true, y: {type: "symlog"}}), /unsupported y scale for aspectRatio: symlog$/); // prettier-ignore
 });
diff --git a/test/plot.js b/test/plot.js
diff --git a/test/scales/scales-test.js b/test/scales/scales-test.js
diff --git a/test/setup.js b/test/setup.js
diff --git a/test/style-test.js b/test/style-test.js
diff --git a/test/transforms/bin-test.js b/test/transforms/bin-test.js
diff --git a/test/transforms/group-test.js b/test/transforms/group-test.js
diff --git a/test/transforms/normalize-test.js b/test/transforms/normalize-test.js
diff --git a/test/transforms/reduce-test.js b/test/transforms/reduce-test.js
diff --git a/test/transforms/stack-test.ts b/test/transforms/stack-test.ts
diff --git a/test/transforms/window-test.js b/test/transforms/window-test.js
diff --git a/test/valueof-test.js b/test/valueof-test.js
diff --git a/vitest.config.ts b/vitest.config.ts
diff --git a/yarn.lock b/yarn.lock

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-import assert from "assert";`
	`1`	`+import {assert} from "vitest";`
`2`	`2`
`3`	`3`	`function warns(run, expected = /warning/i) {`
`4`	`4`	`const actual = [];`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-import assert from "assert";`
	`1`	`+import {assert, it} from "vitest";`
`2`	`2`	`import {readMarkdownFiles, readMarkdownSource, getAnchors, getLinks} from "../docs/components/links.js";`
`3`	`3`
`4`	`4`	`it("documentation links point to existing internal anchors", async () => {`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-import assert from "assert";`
	`1`	`+import {assert, describe, it} from "vitest";`
`2`	`2`	`import {numberInterval} from "../src/options.js";`
`3`	`3`
`4`	`4`	`describe("numberInterval(interval)", () => {`