Conditional assertions #7
Description
So, at the moment, using babel-plugin-unassert, I can't write an assertion within a conditional:
if (options.class) assert(root instanceof options.class)
> BABEL_ENV=production ./build.sh
TypeError: ./giraphe.es6.js: Property consequent of IfStatement expected node to be of a type ["Statement"] but instead got null
at Object.validate (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-types/lib/definitions/index.js:115:13)
at Object.validate (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-types/lib/index.js:552:9)
at NodePath._replaceWith (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-traverse/lib/path/replacement.js:214:7)
at NodePath._remove (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-traverse/lib/path/removal.js:60:10)
at NodePath.remove (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-traverse/lib/path/removal.js:31:8)
at /Users/ec/Documents/Code/.local/giraphe/node_modules/babel-traverse/lib/path/lib/removal-hooks.js:40:12
at NodePath._callRemovalHooks (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-traverse/lib/path/removal.js:51:9)
at NodePath.remove (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-traverse/lib/path/removal.js:25:12)
at PluginPass.visitor.CallExpression.enter (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-plugin-unassert/index.js:57:37)
at newFn (/Users/ec/Documents/Code/.local/giraphe/node_modules/babel-traverse/lib/visitors.js:310:19)
So, I understand the dangers of messing with code around the actual call to the assert; but this particular one is really, really egregious (assertions occur alone behind a conditional all the time!)
Here's my thought for how to deal with it:
-
By default, if assertion-statement being removed is the sole child of a conditional branch, then remove that conditional branch, and insert the condition-expression as a bare statement (incase it was written to have any side-effects):
if (foo(bar)) assert(widget); # becomes foo(bar); -
And provide an option to entirely remove conditionals whose only contents are an assertion (i.e. “I am acknowledging that I know that I need to write my conditional-assertions to have no side-effects, or to include a second statement within their body if they do.”
If this is welcome, I'm happy to write a few failing test-cases and pull-request them. (=