From 167e99db544fd55d20224acf8441debe06a147fd Mon Sep 17 00:00:00 2001
From: n3wbie <r3v4@onbloc.xyz>
Date: Tue, 13 Jun 2023 15:19:10 +0900
Subject: [PATCH] feat: std.TestSetPrevRealm

---
 examples/gno.land/r/demo/inner/inner.gno      |  1 +
 examples/gno.land/r/demo/inner/inner_test.gno | 30 +++++++++++
 gnovm/tests/imports.go                        | 52 +++++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 examples/gno.land/r/demo/inner/inner.gno
 create mode 100644 examples/gno.land/r/demo/inner/inner_test.gno

diff --git a/examples/gno.land/r/demo/inner/inner.gno b/examples/gno.land/r/demo/inner/inner.gno
new file mode 100644
index 00000000000..8a7eab5c415
--- /dev/null
+++ b/examples/gno.land/r/demo/inner/inner.gno
@@ -0,0 +1 @@
+package inner
diff --git a/examples/gno.land/r/demo/inner/inner_test.gno b/examples/gno.land/r/demo/inner/inner_test.gno
new file mode 100644
index 00000000000..0b98a523cd3
--- /dev/null
+++ b/examples/gno.land/r/demo/inner/inner_test.gno
@@ -0,0 +1,30 @@
+package inner
+
+import (
+	"std"
+	"testing"
+
+	"gno.land/p/demo/testutils"
+)
+
+var (
+	oc std.Address = testutils.TestAddress("origin caller ")
+	or string      = "gno.land/r/demo/outer_realm"
+)
+
+func TestOuterCallInner(t *testing.T) {
+	std.TestSetOrigCaller(oc)
+	shouldEQ(t, std.GetOrigCaller(), oc)
+
+	std.TestSetPrevRealm(or)
+	pr := std.PrevRealm()
+	shouldEQ(t, pr.Addr(), std.DerivePkgAddr(or))
+	shouldEQ(t, pr.PkgPath(), or)
+	shouldEQ(t, std.GetOrigCaller(), oc)
+}
+
+func shouldEQ(t *testing.T, got, want interface{}) {
+	if got != want {
+		t.Errorf("got %v, want %v", got, want)
+	}
+}
diff --git a/gnovm/tests/imports.go b/gnovm/tests/imports.go
index 58d62f02d8d..1196564f224 100644
--- a/gnovm/tests/imports.go
+++ b/gnovm/tests/imports.go
@@ -567,6 +567,58 @@ func testPackageInjector(store gno.Store, pn *gno.PackageNode) {
 				m.Context = ctx
 			},
 		)
+		pn.DefineNative("TestSetPrevRealm",
+			gno.Flds( // params
+				"", gno.AnyT(),
+			),
+			gno.Flds( // results
+			),
+			func(m *gno.Machine) {
+				arg0 := m.LastBlock().GetParams1().TV
+
+				switch arg0.T.String() {
+				case "std.Address":
+					// Set PrevRealm as an user
+					addr := arg0.GetString()
+					ctx := m.Context.(stdlibs.ExecContext)
+					ctx.OrigCaller = crypto.Bech32Address(addr)
+					m.Context = ctx
+
+				case "string":
+					// Set PrevRealm as a realm
+					realm := arg0.GetString()
+
+					// overwrite orig caller
+					ctx := m.Context.(stdlibs.ExecContext)
+					ctx.OrigCaller = crypto.Bech32Address(realm)
+
+					// Set PkgPath
+					for i := m.NumFrames() - 1; i > 0; i-- {
+						fr := m.Frames[i]
+						if fr.LastPackage == nil || !fr.LastPackage.IsRealm() {
+							if i != 1 {
+								fr.LastPackage = &gno.PackageValue{
+									PkgPath: "gno.land/r/dummy",
+								}
+
+								m.Frames[i] = fr
+							} else {
+								fr.LastPackage = &gno.PackageValue{
+									PkgPath: realm,
+								}
+
+								m.Frames[i] = fr
+							}
+
+						}
+					}
+				default:
+					panic(
+						fmt.Sprintf("TestSetPrevRealm: invlaid type %v", arg0.T),
+					)
+				}
+			},
+		)
 		pn.DefineNative("TestSetOrigPkgAddr",
 			gno.Flds( // params
 				"", "Address",