Add closure example for wasm_cc_binary (#941)
* Stub out addition of closure_externs_file option in wasm_cc_binary
* WIP
* args are passed, externs cannot be found
* try location
* update tests
diff --git a/bazel/test_external/BUILD b/bazel/test_external/BUILD
index d824f09..4e69238 100644
--- a/bazel/test_external/BUILD
+++ b/bazel/test_external/BUILD
@@ -13,10 +13,14 @@
BASE_LINKOPTS = [
"--bind", # Enable embind
"-sMODULARIZE",
+ "--pre-js",
+ "hello-embind-interface.js",
]
RELEASE_OPTS = [
"--closure=1", # Run the closure compiler
+ # Tell closure about the externs file, so as not to minify our JS public API.
+ "--closure-args=--externs=$(location hello-embind-externs.js)"
]
DEBUG_OPTS = [
@@ -36,6 +40,11 @@
cc_binary(
name = "hello-embind",
srcs = ["hello-embind.cc"],
+ features = ["emcc_debug_link"],
+ additional_linker_inputs = [
+ "hello-embind-externs.js",
+ "hello-embind-interface.js",
+ ],
linkopts = select({
":debug_opts": BASE_LINKOPTS + DEBUG_OPTS,
":release_opts": BASE_LINKOPTS + RELEASE_OPTS,
@@ -50,3 +59,4 @@
name = "hello-embind-wasm",
cc_target = ":hello-embind",
)
+
diff --git a/bazel/test_external/hello-embind-externs.js b/bazel/test_external/hello-embind-externs.js
new file mode 100644
index 0000000..864d220
--- /dev/null
+++ b/bazel/test_external/hello-embind-externs.js
@@ -0,0 +1,2 @@
+// This file prevents customJSFunctionToTestClosure from being minified by the Closure compiler.
+Module.customJSFunctionToTestClosure = function() {}
\ No newline at end of file
diff --git a/bazel/test_external/hello-embind-interface.js b/bazel/test_external/hello-embind-interface.js
new file mode 100644
index 0000000..ddc4d2f
--- /dev/null
+++ b/bazel/test_external/hello-embind-interface.js
@@ -0,0 +1,3 @@
+Module.customJSFunctionToTestClosure = function(firstParam, secondParam) {
+ console.log("This function adds two numbers to get", firstParam + secondParam);
+}
\ No newline at end of file
diff --git a/test/test_bazel.sh b/test/test_bazel.sh
index 5b06692..f52daa4 100755
--- a/test/test_bazel.sh
+++ b/test/test_bazel.sh
@@ -27,5 +27,8 @@
cd test_external
bazel build //:hello-world-wasm
bazel build //:hello-embind-wasm --compilation_mode dbg # debug
+
# Test use of the closure compiler
bazel build //:hello-embind-wasm --compilation_mode opt # release
+# This function should not be minified if the externs file is loaded correctly.
+grep "customJSFunctionToTestClosure" bazel-bin/hello-embind-wasm/hello-embind.js
\ No newline at end of file
