sitegen/framework/css.ts
2025-06-07 17:01:34 -07:00

90 lines
2.3 KiB
TypeScript

export interface Theme {
bg: string;
fg: string;
primary?: string;
h1?: string;
}
export function stringifyTheme(theme: Theme) {
return [
":root {",
"--bg: " + theme.bg + ";",
"--fg: " + theme.fg + ";",
theme.primary ? "--primary: " + theme.primary + ";" : null,
"}",
theme.h1 ? "h1 { color: " + theme.h1 + "}" : null,
].filter(Boolean).join("\n");
}
export function preprocess(css: string, theme: Theme): string {
const keys = Object.keys(theme);
const regex = new RegExp(
`([{};\\n][^{};\\n]*var\\(--(${keys.join("|")})\\).*?(?=[;{}\\n]))`,
"gs",
);
const regex2 = new RegExp(`var\\(--(${keys.join("|")})\\)`);
return css.replace(
regex,
(_, line) =>
line.replace(
regex2,
(_: string, varName: string) => theme[varName as keyof Theme],
) +
";" + line.slice(1),
);
}
export async function bundleCssFiles(
cssImports: string[],
theme: Theme,
dev: boolean = false,
): Promise<string> {
const plugin = {
name: "clover",
setup(b) {
b.onResolve(
{ filter: /^\$input\$$/ },
() => ({ path: ".", namespace: "input" }),
);
b.onLoad(
{ filter: /./, namespace: "input" },
() => ({
loader: "css",
contents:
cssImports.map((path) => `@import url(${JSON.stringify(path)});`)
.join("\n") + stringifyTheme(theme),
resolveDir: ".",
}),
);
b.onLoad(
{ filter: /\.css$/ },
async ({ path: file }) => ({
loader: "css",
contents: preprocess(await fs.readFile(file, "utf-8"), theme),
}),
);
},
} satisfies Plugin;
const build = await esbuild.build({
bundle: true,
entryPoints: ["$input$"],
write: false,
external: ["*.woff2"],
target: ["ie11"],
plugins: [plugin],
minify: !dev,
});
const { errors, warnings, outputFiles } = build;
if (errors.length > 0) {
throw new AggregateError(errors, "CSS Build Failed");
}
if (warnings.length > 0) {
throw new AggregateError(warnings, "CSS Build Failed");
}
if (outputFiles.length > 1) throw new Error("Too many output files");
return outputFiles[0].text;
}
import type { Plugin } from "esbuild";
import * as esbuild from "esbuild";
import * as fs from "./fs.ts";