NodeJs Script that compiles scss files fails because of postcss rule for undefined variables - node.js

Question

I am using scss-bundle to import an scss file and resolve all his #import statements to later save it again as scss file.
This works fine and below is an example to see how it works:
scss-bundle.ts
import { Bundler } from 'scss-bundle';
import { relative } from 'path';
import { writeFile } from 'fs-extra';
/** Bundles all SCSS files into a single file */
async function bundleScss(input, output) {
const {found, bundledContent, imports} = await new Bundler()
.Bundle(input, ['./src/styles/**/*.scss']);
if (imports) {
const cwd = process.cwd();
const filesNotFound = imports
.filter((x) => !x.found)
.map((x) => relative(cwd, x.filePath));
if (filesNotFound.length) {
console.error(`SCSS imports failed \n\n${filesNotFound.join('\n - ')}\n`);
throw new Error('One or more SCSS imports failed');
}
}
if (found) {
await writeFile(output, bundledContent);
}
}
bundleScss('./src/styles/file-to-import.scss', './src/styles/imported-file.scss');
Where file-to-import.scss is the following file:
#import './file-to-import-1';
#import './file-to-import-2';
And file-to-import-1.scss and file-to-import-2.scss are the following files:
file-to-import-1.scss
.price-range {
background-color: $range-header-background-1;
}
file-to-import-2.scss
.qr-code {
background-color: $range-header-background-2;
}
The result of executing the script is:
imported-file.scss:
.price-range {
background-color: $range-header-background-1;
}
.qr-code {
background-color: $range-header-background-2;
}
Until this everything is working well.
Now ... I want to use postcss-css-modules in order to hash the names of the classes, the result should be something like this:
imported-file.scss after being hashed
._3BQkZ {
background-color: $range-header-background-1;
}
.Xb2EV {
background-color: $range-header-background-2;
}
I have already achieved that but only if I define the variables $range-header-background-1 and $range-header-background-2.
However, I can not define the variables yet because I need to defined them on run time as query params of an Http request.
If I run the script without defining the variables the following error is display:
(node:1972) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 2): CssSyntaxError: <css input>:372:14: Unknown word
(node:1972) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
Here is the scss-budle.ts with postcss-css-modules call:
import { Bundler } from 'scss-bundle';
import { relative } from 'path';
import * as path from 'path';
import { writeFile } from 'fs-extra';
import * as postcssModules from 'postcss-modules';
import * as postcss from 'postcss';
import * as fs from 'fs';
/** Bundles all SCSS files into a single file */
async function bundleScss(input, output) {
const {found, bundledContent, imports} = await new Bundler()
.Bundle(input, ['./src/styles/**/*.scss']);
if (imports) {
const cwd = process.cwd();
const filesNotFound = imports
.filter((x) => !x.found)
.map((x) => relative(cwd, x.filePath));
if (filesNotFound.length) {
console.error(`SCSS imports failed \n\n${filesNotFound.join('\n - ')}\n`);
throw new Error('One or more SCSS imports failed');
}
}
if (found) {
await writeFile(output, bundledContent);
const hashedResult = await postcss().use(postcssModules({
generateScopedName: '[hash:base64:5]',
getJSON(cssFileName: any, json: any, outputFileName: any) {
let jsonFileName = path.resolve('./src/styles/imported-file.json');
fs.writeFileSync(jsonFileName, JSON.stringify(json));
}
})).process(bundledContent);
await writeFile(output.replace('.scss', '-hashed.scss'), hashedResult.css, 'utf8');
return;
}
}
bundleScss('./src/styles/file-to-import.scss', './src/styles/imported-file.scss');
Does anybody know how to continue executing postcss-css-modules without stopping because the scss variables are not defined?
Thanks in advance.

Answer 1

I was able to run the script successfully using postcss-scss as parser of postcss:
import * as postcssScss from 'postcss-scss';
...
const hashedResult = await postcss([
postcssModules({
generateScopedName: '[hash:base64:8]',
getJSON(cssFileName: any, json: any, outputFileName: any) {
let jsonFileName = path.resolve('./src/styles/imported-file.json');
fs.writeFileSync(jsonFileName, JSON.stringify(json));
}
})
]).process(bundledContent, { parser: postcssScss});
Below, I leave the script complete:
scss-bundle.ts
import { Bundler } from 'scss-bundle';
import { relative } from 'path';
import * as path from 'path';
import { writeFile } from 'fs-extra';
import * as postcssModules from 'postcss-modules';
import * as postcss from 'postcss';
import * as fs from 'fs';
import * as postcssScss from 'postcss-scss';
/** Bundles all SCSS files into a single file */
async function bundleScss(input, output) {
const {found, bundledContent, imports} = await new Bundler()
.Bundle(input, ['./src/styles/**/*.scss']);
if (imports) {
const cwd = process.cwd();
const filesNotFound = imports
.filter((x) => !x.found)
.map((x) => relative(cwd, x.filePath));
if (filesNotFound.length) {
console.error(`SCSS imports failed \n\n${filesNotFound.join('\n - ')}\n`);
throw new Error('One or more SCSS imports failed');
}
}
if (found) {
await writeFile(output, bundledContent);
const hashedResult = await postcss([
postcssModules({
generateScopedName: '[hash:base64:8]',
getJSON(cssFileName: any, json: any, outputFileName: any) {
let jsonFileName = path.resolve('./src/styles/imported-file.json');
fs.writeFileSync(jsonFileName, JSON.stringify(json));
}
})
]).process(bundledContent, { parser: postcssScss});
await writeFile(output.replace('.scss', '-hashed.scss'), hashedResult.css, 'utf8');
return;
}
}
bundleScss('./src/styles/file-to-import.scss', './src/styles/imported-file.scss');