a/snapasserts: add tests for missing resource revision assertion

asserts/snapasserts/snapasserts_test.go

@@ -844,6 +844,40 @@ func (s *snapassertsSuite) TestCrossCheckResource(c *C) {
 	c.Assert(err, IsNil)
 }
 
+func (s *snapassertsSuite) TestCrossCheckResourceMissingRevisionAssertion(c *C) {
+	s.testCrossCheckResourceMissingRevisionAssertion(c, "")
+}
+
+func (s *snapassertsSuite) TestCrossCheckResourceProvenanceMissingRevisionAssertion(c *C) {
+	s.testCrossCheckResourceMissingRevisionAssertion(c, "prov")
+}
+
+func (s *snapassertsSuite) testCrossCheckResourceMissingRevisionAssertion(c *C, provenance string) {
+	digest := makeDigest(12)
+	const size = uint64(1024)
+	const resourceName = "test-component"
+	const snapID = "snap-id-1"
+
+	si := &snap.SideInfo{
+		SnapID:   "snap-id-1",
+		Revision: snap.R(12),
+	}
+
+	csi := &snap.ComponentSideInfo{
+		Component: naming.NewComponentRef("snap", "test-component"),
+		Revision:  snap.R(24),
+	}
+
+	err := snapasserts.CrossCheckResource(resourceName, digest, provenance, size, csi, si, nil, s.localDB)
+	c.Assert(err, NotNil)
+
+	var suffix string
+	if provenance != "" {
+		suffix = fmt.Sprintf(" provenance: %s", provenance)
+	}
+	c.Assert(err, ErrorMatches, fmt.Sprintf("internal error: cannot find pre-populated snap-resource-revision assertion for %q: %s%s", resourceName, digest, suffix))
+}
+
 func (s *snapassertsSuite) TestCrossCheckResourceProvenance(c *C) {
 	snapRev := snap.R(12)
 	const (