feat: JSON schemas (#70)

* Read JSON schemas

* Separate validation from parsing

* Stop using yaml.MapSlice

* Remove WeightsFromYAML and ToYAML

* Write JSON by default, but continue writing YAML if yaml exists

* Bump the version

* Fix segfault in `testtrack schema generate` (unrelated fix)

* Fix broken symlink detection logic

* Change the signature for `findSchemaPath`

* Update docs/help information to include schema.json

Author: rzane

Makefile

@@ -1,6 +1,6 @@
 SHELL = /bin/sh
 
-VERSION=1.7.1
+VERSION=1.8.0
 BUILD=`git rev-parse HEAD`
 
 LDFLAGS=-ldflags "-w -s \

README.md

@@ -102,7 +102,7 @@ If you have a large organization, you may wish to tag ownership of splits to a s
 
 ### Syncing split assignments
 
-If you want to ensure that your local split assignments are in sync with your remote (production) assignments, you can run `TESTTRACK_CLI_URL=<base_url> testtrack sync` (e.g. `TESTTRACK_CLI_URL=https://tt.example.com testtrack sync`) from your project directory to pull the assignments from your remote server into your local `schema.yml` file.
+If you want to ensure that your local split assignments are in sync with your remote (production) assignments, you can run `TESTTRACK_CLI_URL=<base_url> testtrack sync` (e.g. `TESTTRACK_CLI_URL=https://tt.example.com testtrack sync`) from your project directory to pull the assignments from your remote server into your local `schema.{json,yml}` file.
 
 ## How to Contribute
 

cmds/schema_generate.go

@@ -7,10 +7,10 @@ import (
 
 var schemaGenerateDoc = `
 Reads the migrations in testtrack/migrate and writes the resulting schema state
-to testtrack/schema.yml, overwriting the file if it already exists. Generate
+to testtrack/schema.{json,yml}, overwriting the file if it already exists. Generate
 makes no TestTrack API calls.
 
-In addition to refreshing a schema.yml file that may have been corrupted due to
+In addition to refreshing a schema file that may have been corrupted due to
 a bad merge or bug that produced incorrect schema state, 'schema generate' will
 also validate that migrations merged from multiple development branches don't
 logically conflict, or else it will fail with errors.
@@ -30,7 +30,7 @@ func init() {
 
 var schemaGenerateCmd = &cobra.Command{
 	Use:   "generate",
-	Short: "Generate schema.yml from migration files",
+	Short: "Generate schema.{json,yml} from migration files",
 	Long:  schemaGenerateDoc,
 	Args:  cobra.NoArgs,
 	RunE: func(cmd *cobra.Command, _ []string) error {

cmds/schema_load.go

@@ -6,7 +6,7 @@ import (
 )
 
 var schemaLoadDoc = `
-Loads the testtrack/schema.yml state into TestTrack server. This operation is
+Loads the testtrack/schema.{json,yml} state into TestTrack server. This operation is
 idempotent with a valid, consistent schema file, though might fail if your
 schema file became invalid due to a bad merge or a bug.
 
@@ -27,7 +27,7 @@ func init() {
 
 var schemaLoadCmd = &cobra.Command{
 	Use:   "load",
-	Short: "Load schema.yml state into TestTrack server",
+	Short: "Load schema.{json,yml} state into TestTrack server",
 	Long:  schemaLoadDoc,
 	Args:  cobra.NoArgs,
 	RunE: func(cmd *cobra.Command, _ []string) error {

cmds/server.go

@@ -6,7 +6,7 @@ import (
 )
 
 var serverDoc = `
-Run a fake TestTrack server for local development, backed by schema.yml files
+Run a fake TestTrack server for local development, backed by schema.{json,yml} files
 and nonsense.
 `
 

cmds/sync.go

@@ -48,7 +48,7 @@ func Sync() error {
 		remoteSplit, exists := splitRegistry.Splits[localSplit.Name]
 		if exists {
 			remoteWeights := splits.Weights(remoteSplit.Weights)
-			localSchema.Splits[ind].Weights = remoteWeights.ToYAML()
+			localSchema.Splits[ind].Weights = remoteWeights
 		}
 	}
 

fakeserver/routes.go

@@ -192,7 +192,7 @@ func getV1SplitRegistry() (interface{}, error) {
 	}
 	splitRegistry := map[string]*splits.Weights{}
 	for _, split := range schema.Splits {
-		splitRegistry[split.Name], err = splits.WeightsFromYAML(split.Weights)
+		splitRegistry[split.Name], err = splits.NewWeights(split.Weights)
 		if err != nil {
 			return nil, err
 		}
@@ -208,7 +208,7 @@ func getV2PlusSplitRegistry() (interface{}, error) {
 	splitRegistry := map[string]*v2Split{}
 	for _, split := range schema.Splits {
 		isFeatureGate := splits.IsFeatureGateFromName(split.Name)
-		weights, err := splits.WeightsFromYAML(split.Weights)
+		weights, err := splits.NewWeights(split.Weights)
 		if err != nil {
 			return nil, err
 		}
@@ -231,7 +231,7 @@ func getV4SplitRegistry() (interface{}, error) {
 	v4Splits := make([]v4Split, 0, len(schema.Splits))
 	for _, split := range schema.Splits {
 		isFeatureGate := splits.IsFeatureGateFromName(split.Name)
-		weights, err := splits.WeightsFromYAML(split.Weights)
+		weights, err := splits.NewWeights(split.Weights)
 		if err != nil {
 			return nil, err
 		}

fakeserver/server_test.go

@@ -33,6 +33,17 @@ splits:
     treatment: 40
 `
 
+var otherTestSchema = `{
+  "serializer_version": 1,
+  "schema_version": "2020011774023",
+  "splits": [
+    {
+      "name": "test.json_experiment",
+      "weights": { "control": 50, "treatment": 50 }
+    }
+  ]
+}`
+
 var testAssignments = `
 something_something_enabled: "true"
 `
@@ -52,7 +63,12 @@ func TestMain(m *testing.M) {
 	}
 
 	schemaContent := []byte(testSchema)
-	if err := os.WriteFile(filepath.Join(schemasDir, "test.yml"), schemaContent, 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(schemasDir, "a.yml"), schemaContent, 0644); err != nil {
+		log.Fatal(err)
+	}
+
+	otherSchemaContent := []byte(otherTestSchema)
+	if err := os.WriteFile(filepath.Join(schemasDir, "b.json"), otherSchemaContent, 0644); err != nil {
 		log.Fatal(err)
 	}
 
@@ -140,6 +156,22 @@ func TestSplitRegistry(t *testing.T) {
 		require.Equal(t, 40, treatment.Weight)
 		require.Equal(t, false, split.FeatureGate)
 	})
+
+	t.Run("it loads JSON schemas from home directory", func(t *testing.T) {
+		w := httptest.NewRecorder()
+		h := createHandler()
+
+		h.ServeHTTP(w, httptest.NewRequest("GET", "/api/v2/split_registry", nil))
+
+		require.Equal(t, http.StatusOK, w.Code)
+
+		registry := v2SplitRegistry{}
+		err := json.Unmarshal(w.Body.Bytes(), &registry)
+		require.Nil(t, err)
+
+		require.Equal(t, 50, registry.Splits["test.json_experiment"].Weights["control"])
+		require.Equal(t, 50, registry.Splits["test.json_experiment"].Weights["treatment"])
+	})
 }
 
 func TestVisitorConfig(t *testing.T) {

schema/schema.go

@@ -1,6 +1,7 @@
 package schema
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"os"
@@ -15,12 +16,24 @@ import (
 	"gopkg.in/yaml.v2"
 )
 
+// Finds the path to the schema file (preferring JSON), or returns testtrack/schema.json
+func findSchemaPath() (string, bool) {
+	if _, err := os.Stat("testtrack/schema.json"); err == nil {
+		return "testtrack/schema.json", true
+	}
+	if _, err := os.Stat("testtrack/schema.yml"); err == nil {
+		return "testtrack/schema.yml", true
+	}
+	return "testtrack/schema.json", false
+}
+
 // Read a schema from disk or generate one
 func Read() (*serializers.Schema, error) {
-	if _, err := os.Stat("testtrack/schema.yml"); os.IsNotExist(err) {
+	schemaPath, exists := findSchemaPath()
+	if !exists {
 		return Generate()
 	}
-	schemaBytes, err := os.ReadFile("testtrack/schema.yml")
+	schemaBytes, err := os.ReadFile(schemaPath)
 	if err != nil {
 		return nil, err
 	}
@@ -53,12 +66,21 @@ func Generate() (*serializers.Schema, error) {
 // Write a schema to disk after alpha-sorting its resources
 func Write(schema *serializers.Schema) error {
 	SortAlphabetically(schema)
-	out, err := yaml.Marshal(schema)
+
+	schemaPath, _ := findSchemaPath()
+
+	var out []byte
+	var err error
+	if filepath.Ext(schemaPath) == ".yml" {
+		out, err = yaml.Marshal(schema)
+	} else {
+		out, err = json.MarshalIndent(schema, "", "  ")
+	}
 	if err != nil {
 		return err
 	}
 
-	err = os.WriteFile("testtrack/schema.yml", out, 0644)
+	err = os.WriteFile(schemaPath, out, 0644)
 	if err != nil {
 		return err
 	}
@@ -68,8 +90,9 @@ func Write(schema *serializers.Schema) error {
 
 // Link a schema to the user's home dir
 func Link(force bool) error {
-	if _, err := os.Stat("testtrack/schema.yml"); os.IsNotExist(err) {
-		return errors.New("testtrack/schema.yml does not exist. Are you in your app root dir? If so, call testtrack init_project first")
+	schemaPath, exists := findSchemaPath()
+	if !exists {
+		return errors.New("testtrack/schema.{json,yml} does not exist. Are you in your app root dir? If so, call testtrack init_project first")
 	}
 	dir, err := os.Getwd()
 	if err != nil {
@@ -84,11 +107,12 @@ func Link(force bool) error {
 	if err != nil {
 		return err
 	}
-	path := fmt.Sprintf("%s/schemas/%s.yml", *configDir, dirname)
+	ext := filepath.Ext(schemaPath)
+	path := fmt.Sprintf("%s/schemas/%s%s", *configDir, dirname, ext)
 	if force {
 		os.Remove(path) // If this fails it might just not exist, we'll error on the next line if something else is up
 	}
-	return os.Symlink(dir+"/testtrack/schema.yml", path)
+	return os.Symlink(dir+"/"+schemaPath, path)
 }
 
 // ReadMerged merges schemas linked at ~/testtrack/schemas into a single virtual schema
@@ -97,28 +121,20 @@ func ReadMerged() (*serializers.Schema, error) {
 	if err != nil {
 		return nil, err
 	}
-	paths, err := filepath.Glob(*configDir + "/schemas/*.yml")
+	paths, err := filepath.Glob(*configDir + "/schemas/*.*")
 	if err != nil {
 		return nil, err
 	}
 	var mergedSchema serializers.Schema
 	for _, path := range paths {
-		// Deref symlink
-		fi, err := os.Lstat(path)
-		if err != nil {
-			return nil, err
-		}
-		if fi.Mode()&os.ModeSymlink != 0 {
-			path, err = os.Readlink(path)
-			if err != nil {
-				continue // It's OK if this symlink isn't traversable (e.g. app was uninstalled), we'll just skip it.
-			}
-		}
-		// Read file
 		schemaBytes, err := os.ReadFile(path)
 		if err != nil {
+			if os.IsNotExist(err) {
+				continue // It's OK if this file doesn't exist (e.g. broken symlink, app was uninstalled), we'll just skip it.
+			}
 			return nil, err
 		}
+
 		var schema serializers.Schema
 		err = yaml.Unmarshal(schemaBytes, &schema)
 		if err != nil {
@@ -156,18 +172,18 @@ func mergeLegacySchema(schema *serializers.Schema) error {
 		if !ok {
 			return fmt.Errorf("expected split name, got %v", mapSlice.Key)
 		}
-		weightsYAML, ok := mapSlice.Value.(yaml.MapSlice)
+		weightsYAML, ok := mapSlice.Value.(map[string]int)
 		if !ok {
 			return fmt.Errorf("expected weights, got %v", mapSlice.Value)
 		}
-		weights, err := splits.WeightsFromYAML(weightsYAML)
+		weights, err := splits.NewWeights(weightsYAML)
 		if err != nil {
 			return err
 		}
 
 		schema.Splits = append(schema.Splits, serializers.SchemaSplit{
 			Name:    name,
-			Weights: weights.ToYAML(),
+			Weights: *weights,
 			Decided: false,
 		})
 	}

schemaloaders/schemaloaders.go

@@ -98,7 +98,7 @@ func schemaSplitMigrations(schemaSplit serializers.SchemaSplit) ([]migrations.IM
 
 	if schemaSplit.Decided {
 		var decision *string
-		weights, err := splits.WeightsFromYAML(schemaSplit.Weights)
+		weights, err := splits.NewWeights(schemaSplit.Weights)
 		if err != nil {
 			return nil, fmt.Errorf("schema split %s invalid: %w", schemaSplit.Name, err)
 		}