If all reasonable sources are filtered via skipSource, then show the …

…source as "unknown source" instead of InjectorShell.build (which should be an internal detail).

PiperOrigin-RevId: 358853443

core/src/com/google/inject/spi/Elements.java

@@ -669,7 +669,17 @@ private ElementSource getElementSource() {
         if (stackTraceOption == IncludeStackTraceOption.COMPLETE
             || stackTraceOption == IncludeStackTraceOption.ONLY_FOR_DECLARING_SOURCE) {
           // With the above conditions and assignments 'callStack' is non-null
-          declaringSource = sourceProvider.get(callStack);
+          StackTraceElement callingSource = sourceProvider.get(callStack);
+          // If we've traversed past all reasonable sources and into our internal code, then we
+          // don't know the source.
+          if (callingSource
+                  .getClassName()
+                  .equals("com.google.inject.internal.InjectorShell$Builder")
+              && callingSource.getMethodName().equals("build")) {
+            declaringSource = SourceProvider.UNKNOWN_SOURCE;
+          } else {
+            declaringSource = callingSource;
+          }
         } else { // or if (stackTraceOption == IncludeStackTraceOptions.OFF)
           // As neither 'declaring source' nor 'call stack' is available use 'module source'
           declaringSource = sourceProvider.getFromClassNames(moduleSource.getModuleClassNames());

core/test/com/google/inject/spi/SourcesTest.java

@@ -0,0 +1,47 @@
+package com.google.inject.spi;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.inject.AbstractModule;
+import com.google.inject.Guice;
+import com.google.inject.Module;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests sources are set correctly in elements. */
+@RunWith(JUnit4.class)
+public final class SourcesTest {
+
+  @Test
+  public void entirelyFilteredSourceShowsAsUnknown() {
+    ElementSource source =
+        (ElementSource)
+            Guice.createInjector(
+                    new AbstractModule() {
+                      @Override
+                      protected void configure() {
+                        binder().skipSources(getClass()).bind(String.class).toInstance("Foo");
+                      }
+                    })
+                .getBinding(String.class)
+                .getSource();
+    assertThat(source.getDeclaringSource()).isEqualTo("[unknown source]");
+  }
+
+  @Test
+  public void unfilteredShowsCorrectly() {
+    Module m =
+        new AbstractModule() {
+          @Override
+          protected void configure() {
+            binder().bind(String.class).toInstance("Foo");
+          }
+        };
+    ElementSource source =
+        (ElementSource) Guice.createInjector(m).getBinding(String.class).getSource();
+    StackTraceElement ste = (StackTraceElement) source.getDeclaringSource();
+    assertThat(ste.getClassName()).isEqualTo(m.getClass().getName());
+    assertThat(ste.getMethodName()).isEqualTo("configure");
+  }
+}