Rename semantic_color_types to suffixes

- Run Prettier on preprocessed CSS
- Add comment at the start of every generated CSS file
- Generate multiple files via interpolation in filenames!
- Preprocess brand/*.css, variants.css

scripts/build.js

@@ -12,6 +12,7 @@ import { dirname, join, relative } from 'path';
 import process from 'process';
 import copy from 'recursive-copy';
 import { fileURLToPath } from 'url';
+import { preprocessStylesheet } from './preprocess-css.js';
 import { cdnDir, distDir, docsDir, rootDir, runScript, siteDir } from './utils.js';
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
@@ -36,6 +37,7 @@ async function buildAll() {
     await generateManifest();
     await generateReactWrappers();
     await generateTypes();
+    await preprocessStyles();
     await generateStyles();
 
     // copy everything to unbundled before we generate bundles.
@@ -105,6 +107,23 @@ function generateReactWrappers() {
   return Promise.resolve();
 }
 
+/**
+ * Generate preprocessed CSS
+ */
+async function preprocessStyles() {
+  const preprocessedCSSFiles = await globby(join(rootDir, 'src/styles/**/*.css.njk'));
+
+  if (preprocessedCSSFiles.length > 0) {
+    spinner.start('Preprocessing stylesheets');
+
+    for (let filePath of preprocessedCSSFiles) {
+      await preprocessStylesheet(filePath);
+    }
+
+    spinner.succeed();
+  }
+}
+
 /**
  * Copies theme stylesheets to the dist.
  */
@@ -371,6 +390,7 @@ if (isDeveloping) {
     try {
       const isTestFile = filename.includes('.test.ts');
       const isCssStylesheet = filename.includes('.css');
+      const isPreprocessedStylesheet = filename.endsWith('.css.njk');
       const isComponent =
         filename.includes('components/') && filename.includes('.ts') && !isCssStylesheet && !isTestFile;
 
@@ -381,6 +401,10 @@ if (isDeveloping) {
 
       await regenerateBundle();
 
+      if (isPreprocessedStylesheet || filename.endsWith('src/styles/data.js')) {
+        await preprocessStyles();
+      }
+
       // Copy stylesheets when CSS files change
       if (isCssStylesheet) {
         await generateStyles();

scripts/preprocess-css.js

@@ -0,0 +1,61 @@
+import { readFile, writeFile } from 'fs/promises';
+import nunjucks from 'nunjucks';
+import * as prettier from 'prettier';
+import prettierConfig from '../prettier.config.js';
+import * as globalData from '../src/styles/data.js';
+
+const prelude = inputFilename => `/* DO NOT EDIT THIS FILE. It is generated from "${inputFilename}" */`;
+
+let env = nunjucks.configure({ autoescape: false });
+let filenameVariables = Object.keys(globalData)
+  .filter(key => key.endsWith('s'))
+  .map(key => key.slice(0, -1));
+let filenameVariablesRegex = RegExp(`\\{\\{\\s*(${filenameVariables.join('|')})\\s*\\}\\}`, 'g');
+
+export async function preprocessStylesheet(inputPath) {
+  const content = await readFile(inputPath, 'utf-8');
+  let outputPath = inputPath.replace(/\.njk$/, '');
+  let filename = outputPath.split('/').pop();
+
+  if (filenameVariablesRegex.test(filename)) {
+    // NOTE only supports a single variable right now
+    filenameVariablesRegex.lastIndex = 0;
+    let ret = [];
+
+    for (let match of filename.matchAll(filenameVariablesRegex)) {
+      let variable = match[1];
+      let values = globalData[variable + 's'];
+
+      for (let value of values) {
+        let data = { [variable]: value };
+        let css = await renderCSS(content, { data, inputPath, outputPath });
+
+        // Now use Nunjucks *again*, to render the actual filename
+        let localOutputFilePath = env.renderString(outputPath, data);
+
+        ret.push(writeFile(localOutputFilePath, css, 'utf-8'));
+      }
+    }
+
+    return Promise.all(ret);
+  } else {
+    let css = await renderCSS(content, { inputPath, outputPath });
+    return writeFile(outputPath, css, 'utf-8');
+  }
+
+  // TODO add generated files to .gitignore?
+}
+
+export async function renderCSS(content, { data, inputPath, outputPath } = {}) {
+  let inputFilename = inputPath.split('/').pop();
+  data = data ? { ...globalData, ...data } : globalData;
+  let css = env.renderString(content, data);
+
+  if (prelude) {
+    css = prelude(inputFilename) + '\n' + css;
+  }
+
+  css = await prettier.format(css, { ...prettierConfig, filepath: outputPath });
+
+  return css;
+}

src/styles/brand/base.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "base.css.njk" */
 :where(:root),
 :host,
 :where([class^='wa-theme-'], [class*=' wa-theme-']),
@@ -8,16 +9,20 @@
    * --wa-color-brand-if-lt-N ➡️ 100% if key < N, 0% otherwise
    * --wa-color-brand-if-gte-N ➡️ 100% if key >= N, 0% otherwise
    */
-  --wa-color-brand-if-lt-40: calc(clamp(0, 40 - var(--wa-color-brand-key), 1) * 100%);
-  --wa-color-brand-if-lt-50: calc(clamp(0, 50 - var(--wa-color-brand-key), 1) * 100%);
-  --wa-color-brand-if-lt-60: calc(clamp(0, 60 - var(--wa-color-brand-key), 1) * 100%);
-  --wa-color-brand-if-lt-70: calc(clamp(0, 70 - var(--wa-color-brand-key), 1) * 100%);
-  --wa-color-brand-if-lt-80: calc(clamp(0, 80 - var(--wa-color-brand-key), 1) * 100%);
 
+  --wa-color-brand-if-lt-40: calc(clamp(0, 40 - var(--wa-color-brand-key), 1) * 100%);
   --wa-color-brand-if-gte-40: calc(100% - var(--wa-color-brand-if-lt-40));
+
+  --wa-color-brand-if-lt-50: calc(clamp(0, 50 - var(--wa-color-brand-key), 1) * 100%);
   --wa-color-brand-if-gte-50: calc(100% - var(--wa-color-brand-if-lt-50));
+
+  --wa-color-brand-if-lt-60: calc(clamp(0, 60 - var(--wa-color-brand-key), 1) * 100%);
   --wa-color-brand-if-gte-60: calc(100% - var(--wa-color-brand-if-lt-60));
+
+  --wa-color-brand-if-lt-70: calc(clamp(0, 70 - var(--wa-color-brand-key), 1) * 100%);
   --wa-color-brand-if-gte-70: calc(100% - var(--wa-color-brand-if-lt-70));
+
+  --wa-color-brand-if-lt-80: calc(clamp(0, 80 - var(--wa-color-brand-key), 1) * 100%);
   --wa-color-brand-if-gte-80: calc(100% - var(--wa-color-brand-if-lt-80));
 
   /*
@@ -25,6 +30,7 @@
    * --wa-color-brand-N-max ➡️ var(--color-brand) if key <= N, var(--color-brand-N) otherwise
    * --wa-color-brand-N-min ➡️ var(--color-brand) if key >= N, var(--color-brand-N) otherwise
    */
+
   --wa-color-brand-40-max: color-mix(
     in oklab,
     var(--wa-color-brand) var(--wa-color-brand-if-lt-40),

src/styles/brand/base.css.njk

@@ -0,0 +1,36 @@
+:where(:root),
+:host,
+:where([class^='wa-theme-'], [class*=' wa-theme-']),
+:where([class^='wa-palette-'], [class*=' wa-palette-']),
+:where([class^='wa-brand-'], [class*=' wa-brand-']) {
+  /**
+   * Conditional tokens for use in color-mix()
+   * --wa-color-brand-if-lt-N ➡️ 100% if key < N, 0% otherwise
+   * --wa-color-brand-if-gte-N ➡️ 100% if key >= N, 0% otherwise
+   */
+  {% for tint in ['40', '50', '60', '70', '80'] %}
+  --wa-color-brand-if-lt-{{ tint }}: calc(clamp(0, {{ tint }} - var(--wa-color-brand-key), 1) * 100%);
+  --wa-color-brand-if-gte-{{ tint }}: calc(100% - var(--wa-color-brand-if-lt-{{ tint }}));
+  {% endfor %}
+
+  /*
+   * Convenience tokens for common tint cutoffs
+   * --wa-color-brand-N-max ➡️ var(--color-brand) if key <= N, var(--color-brand-N) otherwise
+   * --wa-color-brand-N-min ➡️ var(--color-brand) if key >= N, var(--color-brand-N) otherwise
+   */
+  {% for tint in ['40', '50', '60', '70'] %}
+  --wa-color-brand-{{ tint }}-max: color-mix(
+    in oklab,
+    var(--wa-color-brand) var(--wa-color-brand-if-lt-{{ tint }}),
+    var(--wa-color-brand-{{ tint }})
+  );
+  --wa-color-brand-{{ tint }}-min: color-mix(
+    in oklab,
+    var(--wa-color-brand) var(--wa-color-brand-if-gte-{{ tint }}),
+    var(--wa-color-brand-{{ tint }})
+  );
+  {% endfor %}
+
+  /* Text color: white if key < 60, brand-10 otherwise */
+  --wa-color-brand-on: color-mix(in oklab, var(--wa-color-brand-10) var(--wa-color-brand-if-gte-60), white);
+}

src/styles/brand/blue.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/cyan.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/gray.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/green.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/indigo.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/pink.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/purple.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/red.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/yellow.css

@@ -1,3 +1,4 @@
+/* DO NOT EDIT THIS FILE. It is generated from "{{ hue }}.css.njk" */
 @import url('base.css');
 
 :where(:root),

src/styles/brand/{{ hue }}.css.njk

@@ -0,0 +1,13 @@
+@import url('base.css');
+
+:where(:root),
+:host,
+:where([class^='wa-theme-'], [class*=' wa-theme-']),
+:where([class^='wa-palette-'], [class*=' wa-palette-']),
+.wa-brand-{{ hue }} {
+  {%- for tint in tints | reverse %}
+  --wa-color-brand-{{ tint }}: var(--wa-color-{{ hue }}-{{ tint }});
+  {%- endfor %}
+  --wa-color-brand: var(--wa-color-{{ hue }});
+  --wa-color-brand-key: var(--wa-color-{{ hue }}-key);
+}

src/styles/data.js

@@ -0,0 +1,6 @@
+/**
+ * Any data relating to the design system.
+ */
+export const hues = ['red', 'yellow', 'green', 'cyan', 'blue', 'indigo', 'purple', 'pink', 'gray'];
+export const tints = ['05', '10', '20', '30', '40', '50', '60', '70', '80', '90', '95'];
+export const variants = ['neutral', 'brand', 'success', 'warning', 'danger'];

src/styles/utilities/variants.css

@@ -1,7 +1,4 @@
-/**
- * Do not edit this file directly. It is generated via variants.css.js
- */
-
+/* DO NOT EDIT THIS FILE. It is generated from "variants.css.njk" */
 /**
  * Register color properties so that the space toggle hack can work.
  */
@@ -64,7 +61,6 @@
  * Element defaults.
    We want these to resolve to inherit when inside a variant, and only be applied when not inside an explicit variant.
  */
-
 :host(wa-button),
 .wa-button,
 button,

src/styles/utilities/variants.css.js

@@ -1,68 +0,0 @@
-/**
- * Generate variants.css
- * To use: node variants.css.js > variants.css
- */
-const variants = ['neutral', 'brand', 'success', 'warning', 'danger'];
-const roles = ['fill', 'border', 'on'];
-const noise = ['loud', 'normal', 'quiet'];
-const defaults = {
-  neutral: [
-    [':host(wa-button)', '.wa-button', 'button', "input[type='button']", "input[type='submit']"],
-    [':host(wa-tag)', '.wa-tag'],
-  ],
-  brand: [
-    [':host(wa-callout)', '.wa-callout'],
-    [':host(wa-badge)', '.wa-badge'],
-  ],
-};
-const types = roles.map(layer => noise.map(priority => layer + '-' + priority)).flat();
-
-let ret = comment('Do not edit this file directly. It is generated via variants.css.js').trimStart();
-
-ret += comment('Register color properties so that the space toggle hack can work.');
-
-for (let type of types) {
-  ret += cssRule(`@property --wa-color-${type}`, [
-    `syntax: '<color>';`,
-    'inherits: true;',
-    'initial-value: transparent;',
-  ]);
-}
-
-ret += comment(`Element defaults.
-   We want these to resolve to inherit when inside a variant, and only be applied when not inside an explicit variant.`);
-
-for (let variant in defaults) {
-  let selector = defaults[variant];
-  let declarations = types.map(type => `--wa-color-${type}: var(--wa-no-variant, var(--wa-color-${variant}-${type}));`);
-
-  ret += cssRule(selector, declarations);
-}
-
-ret += comment('Variants');
-
-for (let variant of variants) {
-  let selector = [`.wa-${variant}`, `:host([variant='${variant}'])`];
-
-  if (variant === 'neutral') {
-    selector.unshift(':root');
-  }
-
-  let declarations = types.map(type => `--wa-color-${type}: var(--wa-color-${variant}-${type});`);
-  ret += cssRule(selector, declarations);
-}
-
-ret += cssRule([variants.map(variant => `.wa-${variant}`), ':host([variant])'], '--wa-no-variant: /* space toggle */;');
-
-console.log(ret.trimEnd());
-
-function cssRule(selector, declarations) {
-  selector = Array.isArray(selector) ? selector.flat().join(',\n') : selector;
-  declarations = Array.isArray(declarations) ? declarations.flat().join('\n') : declarations;
-  declarations = declarations.replace(/^/gm, '  ');
-  return `\n${selector} {\n${declarations}\n}\n`;
-}
-
-function comment(text) {
-  return ['\n/**', ` * ${text}`, ' */\n'].join('\n');
-}

src/styles/utilities/variants.css.njk

@@ -0,0 +1,54 @@
+{% set suffixes = [
+  'fill-loud', 'fill-normal', 'fill-quiet',
+  'border-loud', 'border-normal', 'border-quiet',
+  'on-loud', 'on-normal', 'on-quiet'
+] -%}
+
+/**
+ * Register color properties so that the space toggle hack can work.
+ */
+{% for suffix in suffixes %}
+@property --wa-color-{{ suffix }} {
+  syntax: '<color>';
+  inherits: true;
+  initial-value: transparent;
+}
+{% endfor %}
+
+/**
+ * Element defaults.
+   We want these to resolve to inherit when inside a variant, and only be applied when not inside an explicit variant.
+ */
+:host(wa-button), .wa-button, button, input[type='button'], input[type='submit'],
+:host(wa-tag), .wa-tag {
+  {%- for suffix in suffixes %}
+  --wa-color-{{ suffix }}: var(--wa-no-variant, var(--wa-color-neutral-{{ suffix }}));
+  {%- endfor %}
+}
+
+:host(wa-callout), .wa-callout,
+:host(wa-badge), .wa-badge {
+  {%- for suffix in suffixes %}
+  --wa-color-{{ suffix }}: var(--wa-no-variant, var(--wa-color-brand-{{ suffix }}));
+  {%- endfor %}
+}
+
+/**
+ * Variants
+ */
+{% for variant in variants %}
+{{ ':root,' if variant === 'neutral' }}
+.wa-{{ variant }},
+:host([variant='{{ variant }}']) {
+  {%- for suffix in suffixes %}
+  --wa-color-{{ suffix }}: var(--wa-color-{{ variant }}-{{ suffix }});
+  {%- endfor %}
+}
+{%- endfor %}
+
+{% for variant in variants %}
+.wa-{{ variant }},
+{%- endfor %}
+:host([variant]) {
+  --wa-no-variant: /* space toggle */;
+}