feat: Implement SIDECAR_WITHOUT_DATAFILE

bids-validator/src/issues/list.ts

@@ -123,6 +123,10 @@ export const bidsIssues: IssueDefinitionRecord = {
     reason:
       'There are files in the /stimuli directory that are not utilized in any _events.tsv file.',
   },
+  SIDECAR_WITHOUT_DATAFILE: {
+    severity: 'error',
+    reason: 'A json sidecar file was found without a corresponding data file',
+  },
 }
 
 const hedIssues: IssueDefinitionRecord = {

bids-validator/src/validators/bids.ts

@@ -12,7 +12,7 @@ import { filenameIdentify } from './filenameIdentify.ts'
 import { filenameValidate } from './filenameValidate.ts'
 import { DatasetIssues } from '../issues/datasetIssues.ts'
 import { emptyFile } from './internal/emptyFile.ts'
-import { unusedStimulus } from './internal/unusedFile.ts'
+import { sidecarWithoutDatafile, unusedStimulus } from './internal/unusedFile.ts'
 import { BIDSContext, BIDSContextDataset } from '../schema/context.ts'
 import { parseOptions } from '../setup/options.ts'
 import { hedValidate } from './hed.ts'
@@ -31,6 +31,7 @@ const perContextChecks: ContextCheckFunction[] = [
 
 const perDSChecks: DSCheckFunction[] = [
   (...args) => Promise.resolve(unusedStimulus(...args)),
+  (...args) => Promise.resolve(sidecarWithoutDatafile(...args)),
 ]
 
 /**

bids-validator/src/validators/internal/unusedFile.ts

@@ -30,3 +30,19 @@ export function unusedStimulus(
     issues.addNonSchemaIssue('UNUSED_STIMULUS', unusedStimuli)
   }
 }
+
+const standalone_json = ['dataset_description.json', 'genetic_info.json']
+
+export function sidecarWithoutDatafile(
+  schema: GenericSchema,
+  dsContext: BIDSContextDataset,
+  issues: DatasetIssues,
+): void {
+  const unusedSidecars = [...walkFileTree(dsContext.tree)].filter(
+    (file) => (!file.viewed && file.name.endsWith('.json') &&
+      !standalone_json.includes(file.name)),
+  )
+  if (unusedSidecars.length) {
+    issues.addNonSchemaIssue('SIDECAR_WITHOUT_DATAFILE', unusedSidecars)
+  }
+}