A TypeScript string interpolation library that allows inspecting strings pre-compilation
This library enables string interpolation in TypeScript, allowing you to inspect strings before they are compiled. This is useful for debugging, logging, and code completion through tools like Github Copilot.
npm i @recon-struct/strix
The strix
library takes a deeply nested object of string templates and returns
a function that can be used to interpolate strings. The function takes a key
corresponding to a template and an object of values to interpolate.
String templates are defined as a deeply nested object. The keys are used to
access the templates, and the values are the templates themselves. The templates
can contain placeholders in the form of {{key}}
, where key
is a variable to
be interpolated.
const templates = {
greeting: 'Hello, {{name}}!',
farewell: 'Goodbye, {{name}}!',
} as const
The strix
function returns a function that takes a key and an optional object
of values. It is strongly typed to ensure that the key is a valid key in the
templates object and that the variables object contains all the required keys.
Using the as const
assertion is recommended to ensure that the object of
templates and variables is treated as a readonly object. This enables the string
interpolation function to provide better type checking and code completion.
Tools like Github Copilot can use the literal string returned by the interpolation function to provide better code completion.
const templates = {
greeting: 'Hello, {{name}}!',
farewell: 'Goodbye, {{name}}!',
} as const
const t = strix(templates)
const helloWorld = t('greeting', { name: 'world' } as const) // 'Hello, world!'
The as const
assertion is used to ensure that the object of templates and
variables is treated as a readonly object. This enables the string interpolation
function to provide better type checking and code completion.
You can see in this example that you can achieve better type checking through
the use of as const
.
// With `as const`
const hello1 = t('greeting', { name: 'world' } as const) // 'Hello, world!'
// Without `as const`
const hello2 = t('greeting', { name: 'world' }) // 'Hello, ${string}!'