Added support for capturing snippets from wasm-bindgen (#3087)

This change also adds `*_bg.wasm.d.ts` files to `target = "web"` uses of
`rust_wasm_bindgen` since this was being output by `wasm-bindgen` but
not collected.

docs/src/rust_wasm_bindgen.md

@@ -121,7 +121,7 @@ For additional information, see the [Bazel toolchains documentation][toolchains]
 ## RustWasmBindgenInfo
 
 <pre>
-RustWasmBindgenInfo(<a href="#RustWasmBindgenInfo-js">js</a>, <a href="#RustWasmBindgenInfo-ts">ts</a>, <a href="#RustWasmBindgenInfo-wasm">wasm</a>)
+RustWasmBindgenInfo(<a href="#RustWasmBindgenInfo-js">js</a>, <a href="#RustWasmBindgenInfo-root">root</a>, <a href="#RustWasmBindgenInfo-snippets">snippets</a>, <a href="#RustWasmBindgenInfo-ts">ts</a>, <a href="#RustWasmBindgenInfo-wasm">wasm</a>)
 </pre>
 
 Info about wasm-bindgen outputs.
@@ -132,6 +132,8 @@ Info about wasm-bindgen outputs.
 | Name  | Description |
 | :------------- | :------------- |
 | <a id="RustWasmBindgenInfo-js"></a>js |  Depset[File]: The Javascript files produced by `wasm-bindgen`.    |
+| <a id="RustWasmBindgenInfo-root"></a>root |  str: The path to the root of the `wasm-bindgen --out-dir` directory.    |
+| <a id="RustWasmBindgenInfo-snippets"></a>snippets |  File: The snippets directory produced by `wasm-bindgen`.    |
 | <a id="RustWasmBindgenInfo-ts"></a>ts |  Depset[File]: The Typescript files produced by `wasm-bindgen`.    |
 | <a id="RustWasmBindgenInfo-wasm"></a>wasm |  File: The `.wasm` file generated by `wasm-bindgen`.    |
 

extensions/wasm_bindgen/private/wasm_bindgen.bzl

@@ -57,19 +57,24 @@ def rust_wasm_bindgen_action(*, ctx, toolchain, wasm_file, target_output, flags
     if ctx.attr.out_name:
         out_name = ctx.attr.out_name
 
-    bindgen_wasm_module = ctx.actions.declare_file(out_name + "_bg.wasm")
+    bindgen_wasm_module = ctx.actions.declare_file("{}/{}_bg.wasm".format(ctx.label.name, out_name))
+    snippets = ctx.actions.declare_directory("{}/snippets".format(ctx.label.name))
 
-    js_out = [ctx.actions.declare_file(out_name + ".js")]
+    js_out = [ctx.actions.declare_file("{}/{}.js".format(ctx.label.name, out_name))]
     ts_out = []
     if not "--no-typescript" in flags:
-        ts_out.append(ctx.actions.declare_file(out_name + ".d.ts"))
+        ts_out.append(ctx.actions.declare_file("{}/{}.d.ts".format(ctx.label.name, out_name)))
 
     if target_output == "bundler":
-        js_out.append(ctx.actions.declare_file(out_name + "_bg.js"))
+        js_out.append(ctx.actions.declare_file("{}/{}_bg.js".format(ctx.label.name, out_name)))
         if not "--no-typescript" in flags:
-            ts_out.append(ctx.actions.declare_file(out_name + "_bg.wasm.d.ts"))
+            ts_out.append(ctx.actions.declare_file("{}/{}_bg.wasm.d.ts".format(ctx.label.name, out_name)))
 
-    outputs = [bindgen_wasm_module] + js_out + ts_out
+    elif target_output == "web":
+        if not "--no-typescript" in flags:
+            ts_out.append(ctx.actions.declare_file("{}/{}_bg.wasm.d.ts".format(ctx.label.name, out_name)))
+
+    outputs = [bindgen_wasm_module, snippets] + js_out + ts_out
 
     args = ctx.actions.args()
     args.add("--target", target_output)
@@ -92,6 +97,8 @@ def rust_wasm_bindgen_action(*, ctx, toolchain, wasm_file, target_output, flags
         wasm = bindgen_wasm_module,
         js = depset(js_out),
         ts = depset(ts_out),
+        snippets = snippets,
+        root = bindgen_wasm_module.dirname,
     )
 
 def _rust_wasm_bindgen_impl(ctx):
@@ -107,7 +114,10 @@ def _rust_wasm_bindgen_impl(ctx):
 
     providers = [
         DefaultInfo(
-            files = depset([info.wasm], transitive = [info.js, info.ts]),
+            files = depset(
+                [info.wasm, info.snippets],
+                transitive = [info.js, info.ts],
+            ),
         ),
         info,
     ]

extensions/wasm_bindgen/providers.bzl

@@ -4,6 +4,8 @@ RustWasmBindgenInfo = provider(
     doc = "Info about wasm-bindgen outputs.",
     fields = {
         "js": "Depset[File]: The Javascript files produced by `wasm-bindgen`.",
+        "root": "str: The path to the root of the `wasm-bindgen --out-dir` directory.",
+        "snippets": "File: The snippets directory produced by `wasm-bindgen`.",
         "ts": "Depset[File]: The Typescript files produced by `wasm-bindgen`.",
         "wasm": "File: The `.wasm` file generated by `wasm-bindgen`.",
     },

extensions/wasm_bindgen/rules_js/test/hello_world_wasm_test.js

@@ -9,6 +9,7 @@ const main = async function (typ, dir) {
         "..",
         dir,
         "test",
+        "hello_world_" + typ + "_wasm_bindgen",
         "hello_world_" + typ + "_wasm_bindgen_bg.wasm",
     );
     const buf = fs.readFileSync(wasm_file);