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@Janiczek
Created January 27, 2023 14:50
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#!/usr/bin/env node
// A work around to https://github.com/avh4/elm-format/issues/352
// * Use it in place of elm-format (only some flags are supported)
// * Run it from a directory containing node_modules/elm-format/bin/elm-format (but you can change it below)
function extractFirstRegexMatch(regex, elmCode) {
var match = elmCode.match(regex);
if (!match)
return null
return {
before: elmCode.slice(0, match.index),
matchedGroups: [].slice.call(match, 1),
after: elmCode.slice(match.index + match[0].length),
};
}
function reduceIndent(targetIndent, finalIndent, code) {
var deltaIndent = targetIndent.length - finalIndent.length;
var lines = code.split('\n');
for (var i = 0; i < lines.length && (lines[i] == "" || lines[i].startsWith(targetIndent)); i++) {
lines[i] = lines[i].slice(deltaIndent);
}
return lines.join('\n');
}
function alignDoNotation(elmCode) {
const doNotationRegex = /([ ]+)(.*[<][|])[\n]([ ]+)([\\][_a-zA-Z0-9(){}, ]+ ->[\n])/;
var stuff;
while(stuff = extractFirstRegexMatch(doNotationRegex, elmCode)) {
var firstLineIndent = stuff.matchedGroups[0]
var firstLineContent = stuff.matchedGroups[1]
var secondLineIndent = stuff.matchedGroups[2]
var lambdaArgument = stuff.matchedGroups[3]
// TODO assert firstLineIndent < secondLineIndent
var finalIndent = firstLineIndent;
var targetIndent = secondLineIndent + ' '.repeat(4);
elmCode =
stuff.before
+
firstLineIndent + firstLineContent + ' ' + lambdaArgument
+
reduceIndent(targetIndent, finalIndent, stuff.after)
}
return elmCode
}
//
// Command line stuff
//
function assert_(test, message) {
if (test) return;
console.error('HACK:', message);
process.exit(-1);
}
function exitOnError(error) {
if (!error) return;
console.error(error.message);
process.exit(-1);
}
function mainForCommandLine() {
const fs = require('fs');
//
// Parse args
//
let inputIsStdin = false;
let inputFile = null;
let outputFile = null;
for (let i = 2; i < process.argv.length; i++) {
let [ option, arg ] = process.argv.slice(i);
({
'--output': () => { outputFile = arg; i++; },
'--stdin': () => { inputIsStdin = true; },
'--validate': () => { assert_(false, '--validate is not supported.'); },
'--yes': () => {},
}[option] || (() => { inputFile = option; })
)();
}
assert_(inputFile || inputIsStdin, 'I need an input file or --stdin');
if (!inputIsStdin && !outputFile) {
outputFile = inputFile;
}
const inputStream =
inputIsStdin
? process.stdin
// TODO YOLO
: fs.openSync(inputFile);
//
// Run elm-format
//
let cp = require('child_process');
let result = cp.spawnSync('elm-format', ['--stdin'], {
stdio: [ inputStream, 'pipe', process.stderr ],
encoding: 'utf-8',
});
exitOnError(result.error);
if (result.status !== 0) {
process.exit(result.status);
}
//
// alignDoNotation()
//
const hackFormattedElmCode = alignDoNotation(result.stdout);
//
// Write
//
if (!outputFile) {
process.stdout.write(hackFormattedElmCode);
} else {
fs.writeFile(outputFile, hackFormattedElmCode, 'utf-8', (err) => {
exitOnError(err);
});
}
};
if (require.main === module) {
mainForCommandLine();
}
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