Add tests for promoted methods

We need implicit field reads for calls to promoted methods.
False negative flags have been added to make this pass on main.

ql/test/library-tests/semmle/go/dataflow/PromotedMethods/DataFlowConfig.ql

@@ -0,0 +1,39 @@
+import go
+import TestUtilities.InlineExpectationsTest
+
+class SourceFunction extends Function {
+  SourceFunction() { this.getName() = "source" }
+}
+
+class SinkFunction extends Function {
+  SinkFunction() { this.getName() = "sink" }
+}
+
+class TestConfig extends DataFlow::Configuration {
+  TestConfig() { this = "testconfig" }
+
+  override predicate isSource(DataFlow::Node source) {
+    source = any(SourceFunction f).getACall().getAResult()
+  }
+
+  override predicate isSink(DataFlow::Node sink) {
+    sink = any(SinkFunction f).getACall().getAnArgument()
+  }
+}
+
+class PromotedMethodsTest extends InlineExpectationsTest {
+  PromotedMethodsTest() { this = "PromotedMethodsTest" }
+
+  override string getARelevantTag() { result = "promotedmethods" }
+
+  override predicate hasActualResult(string file, int line, string element, string tag, string value) {
+    exists(TestConfig config, DataFlow::Node source, DataFlow::Node sink |
+      config.hasFlow(source, sink)
+    |
+      sink.hasLocationInfo(file, line, _, _, _) and
+      element = sink.toString() and
+      value = source.getEnclosingCallable().getName() and
+      tag = "promotedmethods"
+    )
+  }
+}

ql/test/library-tests/semmle/go/dataflow/PromotedMethods/methods.go

@@ -0,0 +1,81 @@
+package main
+
+func source() string {
+	return "hello world"
+}
+
+func sink(s string) {}
+
+type Embedded struct {
+	field string
+}
+
+type Base1 struct {
+	Embedded
+}
+
+type Base2 struct {
+	*Embedded
+}
+
+func (e Embedded) sinkFieldOnEmbeddedNonPointerReceiver() {
+	sink(e.field) // $promotedmethods=nonPointerSender1 $promotedmethods=pointerSender1 $promotedmethods=nonPointerSender2 $promotedmethods=pointerSender2
+}
+
+func (e *Embedded) sinkFieldOnEmbeddedPointerReceiver() {
+	sink(e.field) // $f-:promotedmethods=nonPointerSender1 $f-:promotedmethods=pointerSender1 $f-:promotedmethods=nonPointerSender2 $f-:promotedmethods=pointerSender2
+}
+
+func (base1 Base1) sinkFieldOnBase1NonPointerReceiver() {
+	sink(base1.field) // $promotedmethods=nonPointerSender1 $promotedmethods=pointerSender1
+}
+
+func (base1 *Base1) sinkFieldOnBase1PointerReceiver() {
+	sink(base1.field) // $f-:promotedmethods=nonPointerSender1 $promotedmethods=pointerSender1
+}
+
+func (base2 Base2) sinkFieldOnBase2NonPointerReceiver() {
+	sink(base2.field) // $promotedmethods=nonPointerSender2 $promotedmethods=pointerSender2
+}
+
+func (base2 *Base2) sinkFieldOnBase2PointerReceiver() {
+	sink(base2.field) // $f-:promotedmethods=nonPointerSender2 $promotedmethods=pointerSender2
+}
+
+func nonPointerSender1() {
+	var base1 Base1
+	base1.field = source()
+	base1.sinkFieldOnEmbeddedNonPointerReceiver()
+	base1.sinkFieldOnEmbeddedPointerReceiver()
+	base1.sinkFieldOnBase1NonPointerReceiver()
+	base1.sinkFieldOnBase1PointerReceiver()
+}
+
+func pointerSender1() {
+	var base1 Base1
+	base1.field = source()
+	base1p := &base1
+	base1p.sinkFieldOnEmbeddedNonPointerReceiver()
+	base1p.sinkFieldOnEmbeddedPointerReceiver()
+	base1p.sinkFieldOnBase1NonPointerReceiver()
+	base1p.sinkFieldOnBase1PointerReceiver()
+}
+
+func nonPointerSender2() {
+	var base2 Base2
+	base2.field = source()
+	base2.sinkFieldOnEmbeddedNonPointerReceiver()
+	base2.sinkFieldOnEmbeddedPointerReceiver()
+	base2.sinkFieldOnBase2NonPointerReceiver()
+	base2.sinkFieldOnBase2PointerReceiver()
+}
+
+func pointerSender2() {
+	var base2 Base2
+	base2.field = source()
+	base2p := &base2
+	base2p.sinkFieldOnEmbeddedNonPointerReceiver()
+	base2p.sinkFieldOnEmbeddedPointerReceiver()
+	base2p.sinkFieldOnBase2NonPointerReceiver()
+	base2p.sinkFieldOnBase2PointerReceiver()
+}