metamorphic: support --initial-state with --run/compare

Allow supplying an initial state when trying to reproduce a failure.

Author: RaduBerinde

internal/metamorphic/metaflags/meta_flags.go

@@ -49,6 +49,9 @@ type CommonFlags struct {
 	// KeyFormatName is the name of the KeyFormat to use. Defaults to "testkeys".
 	// Acceptable values are "testkeys" and "cockroachkvs".
 	KeyFormatName string
+	// InitialStatePath is the path to a database data directory from a previous
+	// run. See the "initial-state" flag below.
+	InitialStatePath string
 }
 
 // KeyFormat returns the KeyFormat indicated by the flags KeyFormatName.
@@ -105,6 +108,10 @@ func initCommonFlags() *CommonFlags {
 	flag.StringVar(&c.KeyFormatName, "key-format", "testkeys",
 		"name of the key format to use")
 
+	flag.StringVar(&c.InitialStatePath, "initial-state", "",
+		`path to a database's data directory, used to prepopulate the test run's databases.
+		Must be used in conjunction with --previous-ops (unless --run or --compare is used).`)
+
 	return c
 }
 
@@ -161,9 +168,6 @@ type RunFlags struct {
 	// PreviousOps is the path to the ops file of a previous run. See the
 	// "previous-ops" flag below.
 	PreviousOps string
-	// InitialStatePath is the path to a database data directory from a previous
-	// run. See the "initial-state" flag below.
-	InitialStatePath string
 	// InitialStateDesc is a human-readable description of the initial database
 	// state. See "initial-state-desc" flag below.
 	InitialStateDesc string
@@ -202,10 +206,6 @@ with --run-dir or --compare`)
 		`path to an ops file, used to prepopulate the set of keys operations draw from." +
 		Must be used in conjunction with --initial-state`)
 
-	flag.StringVar(&r.InitialStatePath, "initial-state", "",
-		`path to a database's data directory, used to prepopulate the test run's databases.
-		Must be used in conjunction with --previous-ops.`)
-
 	flag.StringVar(&r.InitialStateDesc, "initial-state-desc", "",
 		`a human-readable description of the initial database state.
 		If set this parameter is written to the OPTIONS to aid in
@@ -247,6 +247,9 @@ func (ro *RunOnceFlags) MakeRunOnceOptions() []metamorphic.RunOnceOption {
 	if ro.NumInstances > 1 {
 		onceOpts = append(onceOpts, metamorphic.MultiInstance(ro.NumInstances))
 	}
+	if ro.InitialStatePath != "" {
+		onceOpts = append(onceOpts, metamorphic.RunOnceInitialStatePath(ro.InitialStatePath))
+	}
 	return onceOpts
 }
 

metamorphic/meta.go

@@ -409,6 +409,7 @@ type runOnceOptions struct {
 	failRegexp          *regexp.Regexp
 	numInstances        int
 	keyFormat           KeyFormat
+	initialStatePath    string
 	customOptionParsers map[string]func(string) (CustomOption, bool)
 }
 
@@ -462,6 +463,12 @@ type MultiInstance int
 func (m MultiInstance) apply(ro *runAndCompareOptions) { ro.numInstances = int(m) }
 func (m MultiInstance) applyOnce(ro *runOnceOptions)   { ro.numInstances = int(m) }
 
+// RunOnceInitialStatePath is used to set an initial database state path for a
+// single run.
+type RunOnceInitialStatePath string
+
+func (i RunOnceInitialStatePath) applyOnce(ro *runOnceOptions) { ro.initialStatePath = string(i) }
+
 // RunOnce performs one run of the metamorphic tests. RunOnce expects the
 // directory named by `runDir` to already exist and contain an `OPTIONS` file
 // containing the test run's configuration. The history of the run is persisted
@@ -491,6 +498,10 @@ func RunOnce(t TestingT, runDir string, seed uint64, historyPath string, rOpts .
 	opts := testOpts.Opts
 	require.NoError(t, parseOptions(testOpts, string(optionsData), runOpts.customOptionParsers))
 
+	if runOpts.initialStatePath != "" {
+		testOpts.initialStatePath = runOpts.initialStatePath
+	}
+
 	ops, err := parse(opsData, parserOpts{
 		parseFormattedUserKey:       testOpts.KeyFormat.ParseFormattedKey,
 		parseFormattedUserKeySuffix: testOpts.KeyFormat.ParseFormattedKeySuffix,