expose pruneErrors?:boolean in validation, improve narrowing heuristics, restore test

Author: cscheid

src/core/lib/yaml-schema/validated-yaml.ts

@@ -40,6 +40,7 @@ const isObject = (value: unknown) => {
 export async function readAndValidateYamlFromMappedString(
   mappedYaml: MappedString,
   schema: Schema,
+  pruneErrors = true,
 ): Promise<{
   yaml: { [key: string]: unknown };
   yamlValidationErrors: LocalizedError[];
@@ -57,7 +58,11 @@ export async function readAndValidateYamlFromMappedString(
 
     const yaml = annotation.result;
     if (validateYaml) {
-      const valResult = await validator.validateParse(mappedYaml, annotation);
+      const valResult = await validator.validateParse(
+        mappedYaml,
+        annotation,
+        pruneErrors,
+      );
       return {
         yaml: yaml as { [key: string]: unknown },
         yamlValidationErrors: valResult.errors,

src/core/lib/yaml-validation/validator.ts

@@ -156,6 +156,9 @@ class ValidationContext {
             // suggesting invalid property names is bad if there are other errors to report
             return 10;
           }
+          if (t[0] === "required") {
+            return 0; // we slightly prefer reporting "required" fields.
+          }
           if (t[0] === "type") {
             if (t[1] === "null") {
               return 10; // suggesting a null value is bad.
@@ -634,8 +637,9 @@ export function validate(
   value: AnnotatedParse,
   schema: Schema,
   source: MappedString,
+  pruneErrors = true,
 ): LocalizedError[] {
   const context = new ValidationContext();
 
-  return context.validate(schema, source, value);
+  return context.validate(schema, source, value, pruneErrors);
 }

src/core/lib/yaml-validation/yaml-schema.ts

@@ -62,8 +62,14 @@ export class YAMLSchema {
   async validateParse(
     src: MappedString,
     annotation: AnnotatedParse,
+    pruneErrors = true,
   ) {
-    const validationErrors = validate(annotation, this.schema, src);
+    const validationErrors = validate(
+      annotation,
+      this.schema,
+      src,
+      pruneErrors,
+    );
 
     if (validationErrors.length) {
       const localizedErrors = this.transformErrors(

tests/unit/schema-validation/error-narrowing.test.ts

@@ -51,7 +51,6 @@ baz: 3
       .forSchemaPathToEndWith("required"));
 });
 
-/*
 // deno-lint-ignore require-await
 yamlValidationUnitTest("schema-narrowing", async () => {
   const _s1 = schemaFromString(`
@@ -130,13 +129,29 @@ arrayOf:
 - part: "-----"
 `;
 
-  assertYamlValidationFails(async () => {
+  await assertYamlValidationFails(async () => {
     await readAndThrow(ymlStr, s3);
   }, (e: ValidationError) => {
-    console.log(e);
     return expectValidationError(e)
       .toHaveLength(1)
       .forSchemaPathToEndWith("required");
   });
 });
-*/
+
+yamlValidationUnitTest("error-narrowing", async () => {
+  const schema = schemaFromString(`
+id: error-narrowing-schema-test
+anyOf:
+  - string
+  - record:
+      foo: string
+      bar: string`);
+
+  await assertYamlValidationFails(async () => {
+    await readAndThrow("foo: bar", schema);
+  }, (e: ValidationError) => {
+    return expectValidationError(e)
+      .toHaveLength(1)
+      .forSchemaPathToEndWith("required");
+  });
+});