[WASM] JsInterop - Fix an issue with static native method overloading.

We incorrectly throw an error when we encounter 2 native jsmethod overloads with differing parameter counts. Example:

  @JsMethod
  public static native int test();

  @JsMethod
  public static native int test(int n);

These two generate the same import, because we use a method reference, and so there should be no conflict.

PiperOrigin-RevId: 551897267

transpiler/java/com/google/j2cl/transpiler/backend/wasm/JsImportsGenerator.java

@@ -269,7 +269,11 @@ private void addMethodImport(JsMethodImport newImport) {
                             existingImport.getImportKey());
                       }
 
-                      if (!newImport.getSignature().equals(existingImport.getSignature())) {
+                      if (!newImport.getSignature().equals(existingImport.getSignature())
+                          // Signature doesn't matter if the method import is emitted as a method
+                          // reference. Exclude these in this check.
+                          && !(newImport.emitAsMethodReference()
+                              && existingImport.emitAsMethodReference())) {
                         problems.error(
                             newImport.getMethod().getSourcePosition(),
                             "Native methods '%s' and '%s', importing JavaScript method '%s', have"

transpiler/javatests/com/google/j2cl/integration/java/staticjsmethods/BUILD

@@ -2,12 +2,32 @@ load(
     "//transpiler/javatests/com/google/j2cl/integration:integration_test.bzl",
     "integration_test",
 )
+load("//build_defs:rules.bzl", "j2wasm_library")
 
 package(
     default_applicable_licenses = ["//:j2cl_license"],
     licenses = ["notice"],
 )
 
+j2wasm_library(
+    name = "staticjsmethods-j2wasm",
+    srcs = glob(
+        [
+            "*.java",
+            "*.js",
+        ],
+        exclude = [
+            # .native.js not supported in Wasm.
+            "Main.native.js",
+        ],
+    ),
+    deps = [
+        "//jre/java:javaemul_internal_annotations-j2wasm",
+        "//third_party:gwt-jsinterop-annotations-j2wasm",
+        "//transpiler/javatests/com/google/j2cl/integration/testing:testing-j2wasm",
+    ],
+)
+
 integration_test(
     name = "staticjsmethods",
     srcs = glob([
@@ -17,5 +37,4 @@ integration_test(
     # Contains JsInterop features which are only applicable for JS output.
     enable_jvm_test = False,
     enable_kt = False,
-    enable_wasm = False,
 )

transpiler/javatests/com/google/j2cl/integration/java/staticjsmethods/Main.java

@@ -18,6 +18,7 @@
 import static com.google.j2cl.integration.testing.Asserts.assertTrue;
 import static jsinterop.annotations.JsPackage.GLOBAL;
 
+import javaemul.internal.annotations.Wasm;
 import jsinterop.annotations.JsMethod;
 
 public class Main {
@@ -36,6 +37,7 @@ public static void testJsMethodsCalledByJava() {
     assertTrue(f2(1) == 23);
   }
 
+  @Wasm("nop") // .native.js not supported in Wasm.
   public static void testJsMethodsCalledByJS() {
     assertTrue(callF1(1) == 12);
     assertTrue(callF2(1) == 23);
@@ -50,6 +52,9 @@ public static void testNativeJsMethod() {
     assertTrue(floor(1.5) == 1);
     assertTrue(f3(-1) == 1);
     assertTrue(isFinite(1.0));
+    assertTrue(max(2, 3) == 3);
+    assertTrue(max(2, 3, 4) == 4);
+    assertTrue(max(2.0, 3.0) == 3.0);
   }
 
   public static void testDeepNamespaceNativeJsMethod() {
@@ -65,9 +70,11 @@ public static void main(String... args) {
   }
 
   @JsMethod
+  @Wasm("nop")
   public static native int callF1(int a);
 
   @JsMethod
+  @Wasm("nop")
   public static native int callF2(int a);
 
   @JsMethod(namespace = GLOBAL, name = "Math.floor")
@@ -76,6 +83,15 @@ public static void main(String... args) {
   @JsMethod(namespace = GLOBAL, name = "Math.abs")
   public static native int f3(int d);
 
+  @JsMethod(namespace = GLOBAL, name = "Math.max")
+  public static native int max(int a, int b);
+
+  @JsMethod(namespace = GLOBAL, name = "Math.max")
+  public static native int max(int a, int b, int c);
+
+  @JsMethod(namespace = GLOBAL, name = "Math.max")
+  public static native double max(double a, double b);
+
   @JsMethod(namespace = GLOBAL, name = "isFinite")
   public static native boolean isFinite(double d);
 

transpiler/javatests/com/google/j2cl/readable/java/staticjsmembers/BUILD

@@ -15,6 +15,6 @@ readable_example(
     ]),
     # TODO(b/202515129): Allow dependencies on native code (like js & iOS) in J2KT.
     generate_kt_readables = False,
-    generate_wasm_readables = False,
+    generate_wasm_imports = True,
     deps = ["//third_party:gwt-jsinterop-annotations-j2cl"],
 )

transpiler/javatests/com/google/j2cl/readable/java/staticjsmembers/StaticJsMembers.java

@@ -65,6 +65,15 @@ public static void f2(int a) {}
   @JsMethod(namespace = "foo.Baz", name = "baz")
   public static native boolean f6();
 
+  @JsMethod(namespace = JsPackage.GLOBAL, name = "Math.max")
+  public static native int max(int a, int b);
+
+  @JsMethod(namespace = JsPackage.GLOBAL, name = "Math.max")
+  public static native int max(int a, int b, int c);
+
+  @JsMethod(namespace = JsPackage.GLOBAL, name = "Math.max")
+  public static native double max(double a, double b);
+
   public void test() {
     StaticJsMembers.f1(1);
     f1(1);
@@ -76,6 +85,12 @@ public void test() {
     f4(1.1);
     StaticJsMembers.f5();
     f5();
+    StaticJsMembers.max(1, 2);
+    max(1, 2);
+    StaticJsMembers.max(1, 2, 3);
+    max(1, 2, 3);
+    StaticJsMembers.max(1.0, 2.0);
+    max(1.0, 2.0);
 
     int n = field1;
     n = field2;

transpiler/javatests/com/google/j2cl/readable/java/staticjsmembers/output_closure/StaticJsMembers.impl.java.js.txt

@@ -42,6 +42,12 @@ class StaticJsMembers extends j_l_Object {
   isFinite(1.1);
   Bar.baz();
   Bar.baz();
+  Math.max(1, 2);
+  Math.max(1, 2);
+  Math.max(1, 2, 3);
+  Math.max(1, 2, 3);
+  Math.max(1, 2);
+  Math.max(1, 2);
   let n = StaticJsMembers.$static_field1__staticjsmembers_StaticJsMembers;
   n = StaticJsMembers.$static_field2__staticjsmembers_StaticJsMembers;
   n = Math.PI;

transpiler/javatests/com/google/j2cl/readable/java/staticjsmembers/output_closure/StaticJsMembers.js.mappings.txt

@@ -25,6 +25,12 @@
 [f4(1.1);] => [isFinite(1.1);] "staticjsmembers.StaticJsMembers.test"
 [StaticJsMembers.f5();] => [Bar.baz();] "staticjsmembers.StaticJsMembers.test"
 [f5();] => [Bar.baz();] "staticjsmembers.StaticJsMembers.test"
+[StaticJsMembers.max(1, 2);] => [Math.max(1, 2);] "staticjsmembers.StaticJsMembers.test"
+[max(1, 2);] => [Math.max(1, 2);] "staticjsmembers.StaticJsMembers.test"
+[StaticJsMembers.max(1, 2, 3);] => [Math.max(1, 2, 3);] "staticjsmembers.StaticJsMembers.test"
+[max(1, 2, 3);] => [Math.max(1, 2, 3);] "staticjsmembers.StaticJsMembers.test"
+[StaticJsMembers.max(1.0, 2.0);] => [Math.max(1, 2);] "staticjsmembers.StaticJsMembers.test"
+[max(1.0, 2.0);] => [Math.max(1, 2);] "staticjsmembers.StaticJsMembers.test"
 [int n = field1;] => [let n = StaticJsMembers.$static_field1__staticjsmembers_StaticJsMembers;] "staticjsmembers.StaticJsMembers.test"
 [n] => [n] "n"
 [n = field2;] => [n = StaticJsMembers.$static_field2__staticjsmembers_StaticJsMembers;] "staticjsmembers.StaticJsMembers.test"