overleaf/services/web/webpack-plugins/lezer-grammar-compiler.js

57 lines
1.9 KiB
JavaScript
Raw Normal View History

const fs = require('fs')
const path = require('path')
const modulePath = path.resolve(__dirname, '../scripts/lezer-latex/generate.js')
try {
fs.accessSync(modulePath, fs.constants.W_OK)
const { compile, options } = require(modulePath)
const PLUGIN_NAME = 'lezer-grammar-compiler'
class LezerGrammarCompilerPlugin {
apply(compiler) {
compiler.hooks.make.tap(PLUGIN_NAME, compilation => {
// Add the grammar file to the file paths watched by webpack
compilation.fileDependencies.add(options.grammarPath)
})
compiler.hooks.beforeCompile.tapAsync(
PLUGIN_NAME,
(_compilation, callback) => {
// Check timestamps on grammar and parser files, and re-compile if needed.
// (Note: the compiled parser file is watched by webpack, and so will trigger
// a second compilation immediately after. This seems harmless.)
if (
!fs.existsSync(options.parserOutputPath) ||
!fs.existsSync(options.termsOutputPath)
) {
console.log('Parser does not exist, compiling')
compile()
return callback()
}
fs.stat(options.grammarPath, (err, grammarStat) => {
if (err) {
return callback(err)
}
fs.stat(options.parserOutputPath, (err, parserStat) => {
if (err) {
return callback(err)
}
callback()
if (grammarStat.mtime > parserStat.mtime) {
console.log('Grammar file newer than parser file, re-compiling')
compile()
}
})
})
}
)
}
}
module.exports = { LezerGrammarCompilerPlugin }
} catch {
class NoOpPlugin {
apply() {
console.log('lezer-latex module not present, skipping compile')
}
}
module.exports = { LezerGrammarCompilerPlugin: NoOpPlugin }
}