Memory driver Query should return error for zero results

Signed-off-by: Michael Nelson <minelson@vmware.com>

cmd/helm/rollback_test.go

@@ -23,7 +23,7 @@ import (
 	"helm.sh/helm/v3/pkg/release"
 )
 
-func TestRollbackCmd(t *testing.T) {
+func makeTestReleases() []*release.Release {
 	rels := []*release.Release{
 		{
 			Name:    "funny-honey",
@@ -38,32 +38,35 @@ func TestRollbackCmd(t *testing.T) {
 			Version: 2,
 		},
 	}
+	return rels
+}
 
+func TestRollbackCmd(t *testing.T) {
 	tests := []cmdTestCase{{
 		name:   "rollback a release",
 		cmd:    "rollback funny-honey 1",
 		golden: "output/rollback.txt",
-		rels:   rels,
+		rels:   makeTestReleases(),
 	}, {
 		name:   "rollback a release with timeout",
 		cmd:    "rollback funny-honey 1 --timeout 120s",
 		golden: "output/rollback-timeout.txt",
-		rels:   rels,
+		rels:   makeTestReleases(),
 	}, {
 		name:   "rollback a release with wait",
 		cmd:    "rollback funny-honey 1 --wait",
 		golden: "output/rollback-wait.txt",
-		rels:   rels,
+		rels:   makeTestReleases(),
 	}, {
 		name:   "rollback a release without revision",
 		cmd:    "rollback funny-honey",
 		golden: "output/rollback-no-revision.txt",
-		rels:   rels,
+		rels:   makeTestReleases(),
 	}, {
 		name:      "rollback a release without release name",
 		cmd:       "rollback",
 		golden:    "output/rollback-no-args.txt",
-		rels:      rels,
+		rels:      makeTestReleases(),
 		wantError: true,
 	}}
 	runTestCmd(t, tests)

pkg/storage/driver/memory.go

@@ -106,6 +106,9 @@ func (mem *Memory) Query(keyvals map[string]string) ([]*rspb.Release, error) {
 			return true
 		})
 	}
+	if len(ls) == 0 {
+		return nil, ErrReleaseNotFound
+	}
 	return ls, nil
 }
 

pkg/storage/driver/memory_test.go

@@ -86,19 +86,27 @@ func TestMemoryQuery(t *testing.T) {
 		desc          string
 		xlen          int
 		lbs           map[string]string
+		expectedError error
 	}{
 		{
 			"should be 2 query results",
 			2,
 			map[string]string{"status": "deployed"},
+			nil,
+		},
+		{
+			"should return ErrReleaseNotFound",
+			0,
+			map[string]string{"status": "pending"},
+			ErrReleaseNotFound,
 		},
 	}
 
 	ts := tsFixtureMemory(t)
 	for _, tt := range tests {
 		l, err := ts.Query(tt.lbs)
-		if err != nil {
+		if got, want := err, tt.expectedError; got != want {
-			t.Fatalf("Failed to query: %s\n", err)
+			t.Fatalf("got: %v, want %v", got, want)
 		}
 
 		if tt.xlen != len(l) {