Add output validation against a defined JSON schema

This commit is contained in:
2026-04-27 21:27:19 -05:00
parent 8a95dba276
commit 6cb739be55
14 changed files with 638 additions and 30 deletions

145
schema/output.go Normal file
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package schema
import (
"bytes"
"embed"
"encoding/json"
"fmt"
"sync"
"github.com/santhosh-tekuri/jsonschema/v6"
)
//go:embed output.schema.json
var schemaFS embed.FS
const outputSchemaPath = "output.schema.json"
var (
compiledOutputSchema *jsonschema.Schema
compileOnce sync.Once
compileErr error
)
// Transcript is seriatim's public JSON output contract.
type Transcript struct {
Metadata Metadata `json:"metadata"`
Segments []Segment `json:"segments"`
OverlapGroups []OverlapGroup `json:"overlap_groups"`
}
// Metadata records the pipeline configuration that produced an artifact.
type Metadata struct {
Application string `json:"application"`
Version string `json:"version"`
InputReader string `json:"input_reader"`
InputFiles []string `json:"input_files"`
PreprocessingModules []string `json:"preprocessing_modules"`
PostprocessingModules []string `json:"postprocessing_modules"`
OutputModules []string `json:"output_modules"`
}
// Segment is the public transcript segment shape.
type Segment struct {
ID int `json:"id"`
Source string `json:"source"`
SourceSegmentIndex *int `json:"source_segment_index,omitempty"`
SourceRef string `json:"source_ref,omitempty"`
DerivedFrom []string `json:"derived_from,omitempty"`
Speaker string `json:"speaker"`
Start float64 `json:"start"`
End float64 `json:"end"`
Text string `json:"text"`
Categories []string `json:"categories,omitempty"`
OverlapGroupID int `json:"overlap_group_id,omitempty"`
}
// OverlapGroup describes a detected overlapping speech region.
type OverlapGroup struct {
ID int `json:"id"`
Start float64 `json:"start"`
End float64 `json:"end"`
Segments []string `json:"segments"`
Speakers []string `json:"speakers"`
Class string `json:"class"`
Resolution string `json:"resolution"`
}
// ValidateTranscript validates a typed transcript against the public JSON
// schema and seriatim-specific semantic rules.
func ValidateTranscript(transcript Transcript) error {
if err := validateSemantics(transcript); err != nil {
return err
}
data, err := json.Marshal(transcript)
if err != nil {
return fmt.Errorf("marshal transcript for schema validation: %w", err)
}
return ValidateJSON(data)
}
// ValidateJSON validates serialized output JSON against the public schema.
func ValidateJSON(data []byte) error {
var value any
decoder := json.NewDecoder(bytes.NewReader(data))
decoder.UseNumber()
if err := decoder.Decode(&value); err != nil {
return fmt.Errorf("decode output JSON for schema validation: %w", err)
}
compiled, err := outputSchema()
if err != nil {
return err
}
if err := compiled.Validate(value); err != nil {
return fmt.Errorf("output schema validation failed: %w", err)
}
return nil
}
func outputSchema() (*jsonschema.Schema, error) {
compileOnce.Do(func() {
data, err := schemaFS.ReadFile(outputSchemaPath)
if err != nil {
compileErr = fmt.Errorf("read embedded output schema: %w", err)
return
}
var schemaDocument any
decoder := json.NewDecoder(bytes.NewReader(data))
decoder.UseNumber()
if err := decoder.Decode(&schemaDocument); err != nil {
compileErr = fmt.Errorf("decode embedded output schema: %w", err)
return
}
compiler := jsonschema.NewCompiler()
if err := compiler.AddResource(outputSchemaPath, schemaDocument); err != nil {
compileErr = fmt.Errorf("load embedded output schema: %w", err)
return
}
compiledOutputSchema, compileErr = compiler.Compile(outputSchemaPath)
if compileErr != nil {
compileErr = fmt.Errorf("compile embedded output schema: %w", compileErr)
}
})
return compiledOutputSchema, compileErr
}
func validateSemantics(transcript Transcript) error {
for index, segment := range transcript.Segments {
wantID := index + 1
if segment.ID != wantID {
return fmt.Errorf("segment %d has id %d; want %d", index, segment.ID, wantID)
}
if segment.End < segment.Start {
return fmt.Errorf("segment %d has end %.3f before start %.3f", index, segment.End, segment.Start)
}
}
for index, group := range transcript.OverlapGroups {
if group.End < group.Start {
return fmt.Errorf("overlap_group %d has end %.3f before start %.3f", index, group.End, group.Start)
}
}
return nil
}

98
schema/output.schema.json Normal file
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{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://gitea.maximumdirect.net/eric/seriatim/schema/output.schema.json",
"title": "seriatim output transcript",
"type": "object",
"additionalProperties": false,
"required": ["metadata", "segments", "overlap_groups"],
"properties": {
"metadata": {
"type": "object",
"additionalProperties": false,
"required": [
"application",
"version",
"input_reader",
"input_files",
"preprocessing_modules",
"postprocessing_modules",
"output_modules"
],
"properties": {
"application": { "type": "string" },
"version": { "type": "string" },
"input_reader": { "type": "string" },
"input_files": {
"type": "array",
"items": { "type": "string" }
},
"preprocessing_modules": {
"type": "array",
"items": { "type": "string" }
},
"postprocessing_modules": {
"type": "array",
"items": { "type": "string" }
},
"output_modules": {
"type": "array",
"items": { "type": "string" }
}
}
},
"segments": {
"type": "array",
"items": { "$ref": "#/$defs/segment" }
},
"overlap_groups": {
"type": "array",
"items": { "$ref": "#/$defs/overlap_group" }
}
},
"$defs": {
"segment": {
"type": "object",
"additionalProperties": false,
"required": ["id", "source", "speaker", "start", "end", "text"],
"properties": {
"id": { "type": "integer", "minimum": 1 },
"source": { "type": "string" },
"source_segment_index": { "type": "integer", "minimum": 0 },
"source_ref": { "type": "string" },
"derived_from": {
"type": "array",
"items": { "type": "string" }
},
"speaker": { "type": "string" },
"start": { "type": "number" },
"end": { "type": "number" },
"text": { "type": "string" },
"categories": {
"type": "array",
"items": { "type": "string" }
},
"overlap_group_id": { "type": "integer", "minimum": 1 }
}
},
"overlap_group": {
"type": "object",
"additionalProperties": false,
"required": ["id", "start", "end", "segments", "speakers", "class", "resolution"],
"properties": {
"id": { "type": "integer", "minimum": 1 },
"start": { "type": "number" },
"end": { "type": "number" },
"segments": {
"type": "array",
"items": { "type": "string" }
},
"speakers": {
"type": "array",
"items": { "type": "string" }
},
"class": { "type": "string" },
"resolution": { "type": "string" }
}
}
}
}

191
schema/output_test.go Normal file
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package schema
import (
"strings"
"testing"
)
func TestValidateTranscriptAcceptsValidTranscript(t *testing.T) {
transcript := validTranscript()
if err := ValidateTranscript(transcript); err != nil {
t.Fatalf("validate transcript: %v", err)
}
}
func TestValidateJSONRejectsMissingRequiredField(t *testing.T) {
err := ValidateJSON([]byte(`{
"metadata": {
"application": "seriatim",
"version": "dev",
"input_reader": "json-files",
"input_files": [],
"preprocessing_modules": [],
"postprocessing_modules": [],
"output_modules": []
},
"segments": []
}`))
assertErrorContains(t, err, "overlap_groups")
}
func TestValidateJSONRejectsWrongFieldType(t *testing.T) {
err := ValidateJSON([]byte(`{
"metadata": {
"application": "seriatim",
"version": "dev",
"input_reader": "json-files",
"input_files": [],
"preprocessing_modules": [],
"postprocessing_modules": [],
"output_modules": []
},
"segments": [
{
"id": "1",
"source": "input.json",
"speaker": "Alice",
"start": 1,
"end": 2,
"text": "hello"
}
],
"overlap_groups": []
}`))
assertErrorContains(t, err, "id")
}
func TestValidateJSONRejectsUnexpectedInternalFields(t *testing.T) {
tests := []struct {
name string
field string
}{
{name: "internal ref", field: `"internal_ref": "internal-1",`},
{name: "words", field: `"words": [],`},
}
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
err := ValidateJSON([]byte(`{
"metadata": {
"application": "seriatim",
"version": "dev",
"input_reader": "json-files",
"input_files": [],
"preprocessing_modules": [],
"postprocessing_modules": [],
"output_modules": []
},
"segments": [
{
"id": 1,
` + test.field + `
"source": "input.json",
"speaker": "Alice",
"start": 1,
"end": 2,
"text": "hello"
}
],
"overlap_groups": []
}`))
assertErrorContains(t, err, "additional properties")
})
}
}
func TestValidateTranscriptRejectsMissingOrNonSequentialIDs(t *testing.T) {
tests := []struct {
name string
ids []int
want string
}{
{name: "missing zero id", ids: []int{0}, want: "segment 0 has id 0; want 1"},
{name: "does not start at one", ids: []int{2}, want: "segment 0 has id 2; want 1"},
{name: "gap", ids: []int{1, 3}, want: "segment 1 has id 3; want 2"},
}
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
transcript := validTranscript()
transcript.Segments = transcript.Segments[:0]
for index, id := range test.ids {
transcript.Segments = append(transcript.Segments, Segment{
ID: id,
Source: "input.json",
Speaker: "Alice",
Start: float64(index),
End: float64(index) + 1,
Text: "hello",
})
}
err := ValidateTranscript(transcript)
assertErrorContains(t, err, test.want)
})
}
}
func TestValidateTranscriptRejectsInvalidTiming(t *testing.T) {
transcript := validTranscript()
transcript.Segments[0].Start = 2
transcript.Segments[0].End = 1
err := ValidateTranscript(transcript)
assertErrorContains(t, err, "segment 0 has end")
}
func TestValidateTranscriptRejectsInvalidOverlapGroupTiming(t *testing.T) {
transcript := validTranscript()
transcript.OverlapGroups = []OverlapGroup{
{
ID: 1,
Start: 3,
End: 2,
Segments: []string{"input.json#0"},
Speakers: []string{"Alice"},
Class: "unknown",
Resolution: "unresolved",
},
}
err := ValidateTranscript(transcript)
assertErrorContains(t, err, "overlap_group 0 has end")
}
func validTranscript() Transcript {
sourceIndex := 0
return Transcript{
Metadata: Metadata{
Application: "seriatim",
Version: "dev",
InputReader: "json-files",
InputFiles: []string{"input.json"},
PreprocessingModules: []string{"validate-raw", "normalize-speakers", "trim-text"},
PostprocessingModules: []string{"assign-ids", "validate-output"},
OutputModules: []string{"json"},
},
Segments: []Segment{
{
ID: 1,
Source: "input.json",
SourceSegmentIndex: &sourceIndex,
Speaker: "Alice",
Start: 1,
End: 2,
Text: "hello",
},
},
OverlapGroups: []OverlapGroup{},
}
}
func assertErrorContains(t *testing.T, err error, want string) {
t.Helper()
if err == nil {
t.Fatalf("expected error containing %q", want)
}
if !strings.Contains(err.Error(), want) {
t.Fatalf("expected error containing %q, got %v", want, err)
}
}