A little template tag
function
that strips the leading indent from multi-line ES string templates. It also
strips the first and last lines if they're just whitespace. If you're using template strings to write heredocs, you should try tagging them with theredoc
to tidy them up a bit!
$ npm install theredoc
const theredoc = require('theredoc')
function some () {
function deeply () {
function nested () {
function code () {
console.log(theredoc`
I want to write multipline lines
but don't want to mess up my indenting.
Ok?
`)
}
}
}
}
Will look tidy in the code listing but output no superfluous indents:
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:
//...
} catch (e) {
console.error(`
Something bad happened.
Message: ${e.message}
`)
}
//...
Additionally, the newlines added to retain the formatting of the function call will be retained in the output, which you probably also don't want.
Instead, theredoc
fixes both those issues by letting you write this:
//...
} 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) having stripped 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:
babel-runtime
, which drastically increases
the size of its
install and, because
babel-runtime depends on core-js
, sets a global
object that might be
more appropriate for an app to set than an intermediate lib\t
)?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.