5520b236dd
**Description:** `EsConfig` and `TsConfig` sound like a general configuration for the whole language, while actually it's only about parsing. To avoid a breaking change, I created type aliases that will work without changing the code, while warning the users. **Related issue:** - Closes #9089. |
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.. | ||
fixtures | ||
flavor/acorn | ||
babelgen.js | ||
compare.sh | ||
convert.rs | ||
flavor.rs | ||
package.json | ||
README.md | ||
swcgen.js |
How tests work
The babel-compat tests are mostly written as fixtures, similar to the @babel/parser tests. The src/convert.rs
test runner looks in the fixtures/
directory for input and expected output files. Input files are parsed into an SWC AST and converted to a Babel AST in Rust. Output files are parsed directly into a Babel AST. The two ASTs are then compared, with any differences causing the test to fail.
How to write a test
Step 1: Create a new fixture dir and input file.
mkdir fixtures/my-test
echo "var a = true;" > fixtures/my-test/input.js
Step 2: Generate an output file with the expected Babel AST as JSON. There's a utility script available to help, but you can do this however you like.
# If using the babelgen.js utility, run `npm install` first to get @babel/parser dependency.
node babelgen.js fixtures/my-test/input.js > fixtures/my-test/output.json
Step 3: cargo test
should now pick up your new test automatically.
There's a small, insignificant different between the default Babel AST and the converted one causing my test to fail.
This happens a lot with None
and Some(false)
. You'll probably want to add a normalizer function to the Normalizer visitor in src/normalize/mod.rs
.
Other random utlities
swcgen.js
: Prints the SWC AST as JSON.compare.sh
: prints the Babel and SWC ASTs side-by-side.