52 lines
2 KiB
Markdown
52 lines
2 KiB
Markdown
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# Support for ghcjs
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This branch of servant implements experimental support for
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[ghcjs](https://github.com/ghcjs/ghcjs) for `servant-client`.
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This means it allows you to write Haskell code in terms of `servant-client`,
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compile it with `ghcjs` to javascript and then use it to execute XHRs from a
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browser. The idea is that this should work transparently for the programmer,
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i.e. from a user's perspective it should work exactly as it does when compiled
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with `ghc`.
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## Status
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This branch is experimental.
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Known caveats:
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- Sending bodies in requests doesn't work when using methods `GET` and `HEAD`.
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At least when running the test-suite with node. `GET` and `HEAD` requests are
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not supposed to have request bodies and [xhr2](https://www.npmjs.com/package/xhr2)
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-- which we use to issue XHRs from node -- discards the request bodies for `GET` and
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`HEAD` requests. (This might actually work in some browsers, no clue.) This causes one
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failing test in the test-suite.
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- We don't have CI for running the test-suite with `ghcjs`. We tried to make
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that work, but failed miserably. That's the main reason why this is not merged
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to `master`.
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- `servant-client` uses libraries that are not optimized for `ghcjs`. I haven't
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investigated this much, but I could imagine that e.g. a native javascript JSON
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parser would be much faster than `aeson` compiled by `ghcjs`.
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## Getting it to work
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The `stack` file that is used to run the test-suite with `ghcjs` may provide
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some inspiration: `servant-client/test/ghcjs/stack-ghcjs.yaml`.
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## Running the tests
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You can run the tests by doing:
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``` bash
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./servant-client/test/ghcjs/run-tests.sh
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```
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## Further development
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I propose to use the branch `client-ghcjs` as a place for further development
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on `ghcjs` support for `servant-client`. We could
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- create PRs against the branch,
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- for releases on `master` merge `master` into this branch to not fall behind,
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- maybe even create tags, e.g. `ghcjs-v0.6` and `ghcjs-v0.7.1` to give people
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fixed commits to stick to.
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