Awesome
genes
Generates split ES6 modules and Typescript definitions from Haxe modules.
Requires Haxe 4+
Usage
<pre><a href="https://github.com/lix-pm/lix.client">lix</a> +lib genes</pre>Install the library and add -lib genes to your hxml.
Defines
| Define | Description |
|---|---|
-D dts | generate Typescript definition files |
-debug or -D js-source-map | generate source maps |
-D source_map_content | include source map contents |
-D genes.unchanged_no_rewrite | don't write output files if there's no change (compares output to file on disk) |
-D genes.extern_init_warning | display a warning wherever an extern __init__ is used as these are not generated by genes |
-D genes.disable | disable genes completely (eg. to compare results to default haxe js generator) |
-D genes.no_extension | do not use the .js extension in import paths |
-D genes.disable_native_accessors | do not generate native getter/setters for properties |
-D genes.banner | string to be inserted at the beginning of every generated .js file |
-D genes.dts_banner | string to be inserted at the beginning of every generated .d.ts file |
-D genes.enum_discriminator | emit extra field in enum instance with value equal to the enum constructor name, useful for native js code to consume the enum instead of relying on the default _hx_index field. Example -D genes.enum_discriminator=_kind |
Metadata
| Metadata | Description |
|---|---|
@:genes.disableNativeAccessors | on class level or field level to disable generation of native getter/setters for properties |
@:genes.type('MyType') | overwrite Typescript type in declarations (use on: class, class properties, typedef, type parameters, ....) |
@:genes.returnType('MyType') | overwrite Typescript return type in declarations (use on functions) |
Dynamic imports
import genes.Genes.dynamicImport;
import my.module.A;
import my.module.B;
import my.module.C;
// ...
dynamicImport(A -> new A()).then(trace);
dynamicImport((B, C) -> [new B(), new C()]).then(trace);
Roughly translates to:
import("./my/module/A")
.then(({ A }) => new A())
.then(console.log);
Promise.all([import("./my/module/B"), import("./my/module/C")])
.then((modules) => [new modules[0].B(), new modules[1].C()])
.then(console.log);
Genes expects a function declaration expression (EFunction) as the sole argument of dynamicImport and it will do 2 things:
- For each argument, take the argument name (e.g. "MyClass") and resolve it as a type in the current context, taking Haxe
importstatements into account. This is for preparing the relative path of the target files (e.g.'../../MyClass.js'). - Type the function body in the current context, ignoring the fact that it is a function body. Thus in the example the scope of
Ais not the function argument but in current context i.e. the actual typeclass A {...}. The return type is then applied as the type parameter ofjs.lib.Promise. This is for hinting the return type of thedynamicImport(...)call so that the compiler can do its typing job properly.
Upstream issues
-
Performance could be much improved if we could use the compiler to output code. Haxe exposes methods to do so, but without a way to generate source maps for them.
-
Typescript definitions are pretty much complete. In some cases though there will be references to non-existing types. Haxe does not pass any types that are removed through DCE to the generation phase. However it does pass every typedef used in the project. This means sometimes a type (which it itself is not used) will reference a type that does not exist (removed by DCE). Luckily Typescript won't warn about these issues when your definitions are included as a library but ideally we'd be able to output completely valid types.