Add test for aliasing interface method definitions

go/ql/test/library-tests/semmle/go/aliases/MethodDefs/methods.go

@@ -0,0 +1,16 @@
+package aliases
+
+type IntAlias = int
+
+type S1 = struct{ x int }
+type S2 = struct{ x IntAlias }
+
+type I1 = interface{ F(int) }
+type I2 = interface{ F(IntAlias) }
+type I3 = interface{ F(S1) }
+type I4 = interface{ F(S2) }
+
+func Test1(param1 I1, param2 I3, arg int) {
+	param1.F(arg)
+	param2.F(S1{arg})
+}

go/ql/test/library-tests/semmle/go/aliases/MethodDefs/test.expected

@@ -0,0 +1,20 @@
+distinctDefinedFs
+| 2 |
+declaredEntities
+| methods.go:3:6:3:13 | IntAlias (1 declaration sites) |
+| methods.go:5:6:5:7 | S1 (1 declaration sites) |
+| methods.go:5:19:5:19 | x (2 declaration sites) |
+| methods.go:6:6:6:7 | S2 (1 declaration sites) |
+| methods.go:6:19:6:19 | x (2 declaration sites) |
+| methods.go:8:6:8:7 | I1 (1 declaration sites) |
+| methods.go:8:22:8:22 | F (2 declaration sites) |
+| methods.go:9:6:9:7 | I2 (1 declaration sites) |
+| methods.go:9:22:9:22 | F (2 declaration sites) |
+| methods.go:10:6:10:7 | I3 (1 declaration sites) |
+| methods.go:10:22:10:22 | F (2 declaration sites) |
+| methods.go:11:6:11:7 | I4 (1 declaration sites) |
+| methods.go:11:22:11:22 | F (2 declaration sites) |
+| methods.go:13:6:13:10 | Test1 (1 declaration sites) |
+| methods.go:13:12:13:17 | param1 (1 declaration sites) |
+| methods.go:13:23:13:28 | param2 (1 declaration sites) |
+| methods.go:13:34:13:36 | arg (1 declaration sites) |

go/ql/test/library-tests/semmle/go/aliases/MethodDefs/test.ql

@@ -0,0 +1,24 @@
+import go
+
+newtype TEntityWithDeclInfo =
+  MkEntityWithDeclInfo(Entity e, int nDecls) { nDecls = count(e.getDeclaration()) and nDecls > 0 }
+
+class EntityWithDeclInfo extends TEntityWithDeclInfo {
+  string toString() {
+    exists(Entity e, int nDecls | this = MkEntityWithDeclInfo(e, nDecls) |
+      result = e.toString() + " (" + nDecls + " declaration sites)"
+    )
+  }
+
+  predicate hasLocationInfo(
+    string filepath, int startline, int startcolumn, int endline, int endcolumn
+  ) {
+    exists(Entity e | this = MkEntityWithDeclInfo(e, _) |
+      e.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn)
+    )
+  }
+}
+
+query predicate distinctDefinedFs(int ct) { ct = count(DeclaredFunction e | e.toString() = "F") }
+
+query predicate declaredEntities(EntityWithDeclInfo e) { any() }