fix scale.domain implementation (#381)

* fix scale.domain implementation
* chore: make sure tests are run in CI
* install @changeset/changeset
* add changeset

Author: gka

.changeset/README.md

@@ -0,0 +1,8 @@
+# Changesets
+
+Hello and welcome! This folder has been automatically generated by `@changesets/cli`, a build tool that works
+with multi-package repos, or single-package repos to help you version and publish your code. You can
+find the full documentation for it [in our repository](https://github.com/changesets/changesets)
+
+We have a quick list of common questions to get you started engaging with this project in
+[our documentation](https://github.com/changesets/changesets/blob/main/docs/common-questions.md)

.changeset/config.json

@@ -0,0 +1,11 @@
+{
+  "$schema": "https://unpkg.com/@changesets/config@3.1.2/schema.json",
+  "changelog": "@changesets/cli/changelog",
+  "commit": false,
+  "fixed": [],
+  "linked": [],
+  "access": "restricted",
+  "baseBranch": "main",
+  "updateInternalDependencies": "patch",
+  "ignore": []
+}

.changeset/scale-domain-no-args.md

@@ -0,0 +1,5 @@
+---
+'chroma-js': minor
+---
+
+scale.domain now returns the original domain array when called with no arguments

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+
+jobs:
+  lint-and-test:
+    runs-on: ubuntu-latest
+    env:
+      CI: true
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10.24.0
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Lint
+        run: pnpm lint
+
+      - name: Test
+        run: pnpm test -- --run

LICENSE

@@ -1,6 +1,6 @@
 chroma.js - JavaScript library for color conversions
 
-Copyright (c) 2011-2024, Gregor Aisch
+Copyright (c) 2011-2025, Gregor Aisch
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without

package.json

@@ -51,7 +51,7 @@
   },
   "main": "./index.js",
   "scripts": {
-    "prepublishOnly": "npm test -- --run && node .bin/update-version.cjs && npm run build",
+    "prepublishOnly": "npm test -- --run && node .bin/update-version.cjs && npm run build && npm run docs",
     "build": "rollup -c && cross-env DEV=1 rollup -c ",
     "docs": "cd docs && make",
     "docs-preview": "cd docs && make && make preview",

src/generator/scale.js

@@ -12,6 +12,7 @@ export default function (colors) {
     let _nacol = chroma('#ccc');
     let _spread = 0;
     // const _fixed = false;
+    let _positions = [0, 1];
     let _domain = [0, 1];
     let _pos = [];
     let _padding = [0, 0];
@@ -180,9 +181,9 @@ export default function (colors) {
         if (classes != null) {
             if (type(classes) === 'array') {
                 _classes = classes;
-                _domain = [classes[0], classes[classes.length - 1]];
+                _positions = [classes[0], classes[classes.length - 1]];
             } else {
-                const d = chroma.analyze(_domain);
+                const d = chroma.analyze(_positions);
                 if (classes === 0) {
                     _classes = [d.min, d.max];
                 } else {
@@ -196,8 +197,11 @@ export default function (colors) {
 
     f.domain = function (domain) {
         if (!arguments.length) {
-            return _pos.map(p => _min + p * (_max - _min));;
+            // return original domain
+            return _domain;
         }
+        // store original domain so we can return it later
+        _domain = domain.slice(0);
         _min = domain[0];
         _max = domain[domain.length - 1];
         _pos = [];
@@ -228,7 +232,7 @@ export default function (colors) {
                 }
             }
         }
-        _domain = [_min, _max];
+        _positions = [_min, _max];
         return f;
     };
 
@@ -324,8 +328,8 @@ export default function (colors) {
         } else if (numColors === 1) {
             result = [f(0.5)];
         } else if (numColors > 1) {
-            const dm = _domain[0];
-            const dd = _domain[1] - dm;
+            const dm = _positions[0];
+            const dd = _positions[1] - dm;
             result = __range__(0, numColors, false).map((i) =>
                 f(dm + (i / (numColors - 1)) * dd)
             );
@@ -342,7 +346,7 @@ export default function (colors) {
                     samples.push((_classes[i - 1] + _classes[i]) * 0.5);
                 }
             } else {
-                samples = _domain;
+                samples = _positions;
             }
             result = samples.map((v) => f(v));
         }

test/scales.test.js

@@ -413,22 +413,21 @@ describe('Some tests for scale()', () => {
 
     describe('multi-stop domain with matching ramp stops', () => {
         const f = scale(['yellow', 'red', 'black']).domain([0, 25, 100]);
-    
+
         it('returns the original domain positions', () => {
             expect(f.domain()).toEqual([0, 25, 100]);
         });
-    
+
         it('maps first stop', () => {
             expect(f(0).hex()).toBe('#ffff00');
         });
-    
+
         it('maps mid stop', () => {
-            expect(f(25).hex()).toBe('#ff8080');
+            expect(f(25).hex()).toBe('#ff0000');
         });
-    
+
         it('maps last stop', () => {
             expect(f(100).hex()).toBe('#000000');
         });
     });
-
 });