A babel plugin that kills javascript's coercion and other silent failure
npm install babel-plugin-fail-explicitbabel-plugin-fail-explicit
==========================
A babel plugin that prevents coercion and silent failure in JavaScript
⚠️ Experimental ⚠️
||), on by default⚠️ This doesn't work as expected with "transform-es2015-modules-umd" at the moment ⚠️
bash
npm install --save-dev babel-plugin-fail-explicit
npm install --save-dev babel-plugin-transform-es2015-modules-commonjs
`Setup
js
// .babelrc
{
"plugins": [
"transform-es2015-modules-commonjs",
"fail-explicit"
]
}
`$3
js
// ------------------------------------------------
// Coercion safeguard
// ------------------------------------------------
[] + {}
// TypeError: 'Unexpected coercion of type "Array" and
// type "Object" using "+" operator'NaN + undefined
// TypeError: Unexpected coercion of type "NaN" and type
// "undefined" using "+" operator
1 + 'some'
// '1some'
// ------------------------------------------------
// Safe Comparison
// ------------------------------------------------
new String('12') > 12
// TypeError: Unexpected comparison of type "String" and type
// "number" using ">" operator
null > undefined
// TypeError: Unexpected comparison of type "null" and type
// "undefined" using ">" operator
// ------------------------------------------------
// Usage for better undefined propagation errors
// ------------------------------------------------
const obj = {
foo: {
bar: {
baz: false
}
}
}
obj.foo.bar._MOO_.baz;
// TypeError: Property "_MOO_" does not exist in "Object.foo._MOO_"
// ------------------------------------------------
// Usage as out of bounds check
// ------------------------------------------------
const some = new Array(3)
some[10]
// TypeError: '"Array[10]" is out of bounds'
// TypeError: '"woo[1]" is out of bounds'
const obj = {
woo: ['']
}
obj.woo[1]
// TypeError: '"woo[1]" is out of bounds'
``