budibase/packages/string-templates/src/helpers/javascript.js

57 lines
1.7 KiB
JavaScript

const { atob } = require("../utilities")
const { cloneDeep } = require("lodash/fp")
const { LITERAL_MARKER } = require("../helpers/constants")
// The method of executing JS scripts depends on the bundle being built.
// This setter is used in the entrypoint (either index.cjs or index.mjs).
let runJS
module.exports.setJSRunner = runner => (runJS = runner)
// Helper utility to strip square brackets from a value
const removeSquareBrackets = value => {
if (!value || typeof value !== "string") {
return value
}
const regex = /\[+(.+)]+/
const matches = value.match(regex)
if (matches && matches[1]) {
return matches[1]
}
return value
}
// Our context getter function provided to JS code as $.
// Extracts a value from context.
const getContextValue = (path, context) => {
let data = context
path.split(".").forEach(key => {
if (data == null || typeof data !== "object") {
return null
}
data = data[removeSquareBrackets(key)]
})
return data
}
// Evaluates JS code against a certain context
module.exports.processJS = (handlebars, context) => {
try {
// Wrap JS in a function and immediately invoke it.
// This is required to allow the final `return` statement to be valid.
const js = `function run(){${atob(handlebars)}};run();`
// Our $ context function gets a value from context.
// We clone the context to avoid mutation in the binding affecting real
// app context.
const sandboxContext = {
$: path => getContextValue(path, cloneDeep(context)),
}
// Create a sandbox with our context and run the JS
const res = { data: runJS(js, sandboxContext) }
return `{{${LITERAL_MARKER} js_result-${JSON.stringify(res)}}}`
} catch (error) {
return "Error while executing JS"
}
}