A string template tag to strip leading indents from your heredoc-style multi-line strings
npm install theredocA little tag function that strips leading indent from multi-line ES string
templates. It also strips the first and last lines if they're just whitespace.
``
$ npm install theredoc
` js
const theredoc = require('theredoc')
console.log(theredoc
I want to write multipline lines
but don't want to mess up my indenting.
Ok?)`
Will output:
`
I want to write multipline lines
but don't want to mess up my indenting.
Ok?
Because good messages are often long messages, but out-of-the-box, ES template
strings
don't format multi-line error and console messages gracefully.
If you're familiar with """-style heredocs from CoffeeScript or the<<~-style heredoc from Ruby 2.3, you might appreciate being able to write
multi-line strings with an indentation level that matches the surrounding code
listing _without_ indenting the resulting string itself.
For example, if you want to print a multi-line error message without superfluous
indentation in the following situation, an unadorned template string would have
to be outdented awkwardly:
`js
//...
} catch (e) {
console.error(
Something bad happened.
Message: ${e.message}
)`
}
//...
Additionally, to format the string neatly at all in the above will also add a
extraneous leading and trailing line containing nothing but whitespace.
Instead, theredoc lets you write this:
`js
//...
} catch (e) {
console.error(theredoc
Something bad happened.
Message: ${e.message}
)`
}
//...
And the resulting console output will be:
`
Something bad happened.
Message: LOL errors
`
With the leading 10 spaces stripped from each line and (since they only contain
whitespace) stripping the first and last lines of the template string.
If you still don't think this is nifty, I don't know what to tell you!
The very cool and fancy library
common-tags can accomplish the
same thing with the stripIndent function it exports, however there are a few
downsides:
* It will trim all leading and trailing whitespace, which one might want to
preserve
* It has a runtime dependency on babel-runtime, which drastically increasescore-js
the size of its
install and, because
babel-runtime depends on , sets a global
object that might be
more appropriate for an app to set than an intermediate lib
* While common-tags is really spiffy and you should check it out to learn about
all the cool transforms you can do, 99.9% of the time I really just want
indent-stripping heredocs
Theredoc only deals with space character indentation, sorry!
A pull request to support tabs would be considered if (a) it didn't drastically
increase the module's complexity, and (b) deferred to counting spaces in the
event that the given string had some lines indented with spaces and other with
\t` tabs.