outdent
Removes leading indentation from ES6 template strings
ES6 template strings are great, but they preserve everything between the backticks, including leading spaces. Sometimes I want to indent my template literals to make my code more readable without including all those spaces in the string.
Outdent will remove those leading spaces, as well as the leading and trailing newlines.
import outdent from 'outdent';
const markdown = outdent`
# My Markdown File
Here is some indented code:
console.log("hello world!");
`;
console.log(markdown);
fs.writeFileSync('output.md', markdown);
The contents of
output.md
do not have the leading indentation:# My Markdown File
Here is some indented code:
console.log("hello world!");
As a Javascript string:var markdown = '# My Markdown File\n' +
'\n' +
'Here is some indented code:' +
'\n' +
' console.log("hello world!");';
You can pass options to outdent to control its behavior. They are explained in Options.
const output = outdent({trimLeadingNewline: false, trimTrailingNewline: false})`
Hello world!
`;
assert(output === '\nHello world!\n');
You can explicitly specify the indentation level by passing outdent
as the first interpolated value. Its position
sets the indentation level and it is removed from the output.const output = outdent`
${outdent}
Yo
12345
Hello world
`;
assert(output === ' Yo\n345\n Hello world');
Note:
${outdent}
must be alone on its own line without anything before or after it. It cannot be preceded by any non-whitespace characters.
If these conditions are not met, outdent will follow normal indentation-detection behavior.Options
trimLeadingNewline
Default: truetrimTrailingNewline
Default: trueWhether or not outdent should remove the leading and/or trailing newline from your template string. For example:
var s = outdent({trimLeadingNewline: false})`
Hello
`;
assert(s === '\nHello');
s = outdent({trimTrailingNewline: false})`
Hello
`
assert(s === 'Hello\n');
s = outdent({trimLeadingNewline: false, trimTrailingNewline: false})`
`;
assert(s === '\n\n');
Gotchas
Start on a new line
Start the contents of your template string on a new line after the opening backtick. Otherwise, outdent has no choice but to detect indentation from the second line, which does not work in all situations.// Bad
const output = outdent `* item 1
* sub-item
`;
// output === '* item 1\n* sub-item'; Indentation of sub-item is lost
// Good
const output = outdent `
* item 1
* sub-item
`;