File size: 1,662 Bytes
bc20498 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 |
export function dedent(
templ: TemplateStringsArray | string,
...values: unknown[]
): string {
let strings = Array.from(typeof templ === 'string' ? [templ] : templ);
// 1. Remove trailing whitespace.
strings[strings.length - 1] = strings[strings.length - 1].replace(
/\r?\n([\t ]*)$/,
'',
);
// 2. Find all line breaks to determine the highest common indentation level.
const indentLengths = strings.reduce((arr, str) => {
const matches = str.match(/\n([\t ]+|(?!\s).)/g);
if (matches) {
return arr.concat(
matches.map((match) => match.match(/[\t ]/g)?.length ?? 0),
);
}
return arr;
}, <number[]>[]);
// 3. Remove the common indentation from all strings.
if (indentLengths.length) {
const pattern = new RegExp(`\n[\t ]{${Math.min(...indentLengths)}}`, 'g');
strings = strings.map((str) => str.replace(pattern, '\n'));
}
// 4. Remove leading whitespace.
strings[0] = strings[0].replace(/^\r?\n/, '');
// 5. Perform interpolation.
let string = strings[0];
values.forEach((value, i) => {
// 5.1 Read current indentation level
const endentations = string.match(/(?:^|\n)( *)$/)
const endentation = endentations ? endentations[1] : ''
let indentedValue = value
// 5.2 Add indentation to values with multiline strings
if (typeof value === 'string' && value.includes('\n')) {
indentedValue = String(value)
.split('\n')
.map((str, i) => {
return i === 0 ? str : `${endentation}${str}`
})
.join('\n');
}
string += indentedValue + strings[i + 1];
});
return string;
}
export default dedent;
|