fix: do not report duplicate keys errors for keys added by merge keys (…

…#25)

* fix: do not report duplicate keys errors for keys added by merge keys

* test: extra override scenario

src/__tests__/fixtures/merge-keys-with-duplicate-props.yaml

@@ -0,0 +1,36 @@
+openapi: 3.0.0
+
+x-format-version: "1.0"
+
+info:
+ title: Merge key issue
+ description: https://yaml.org/type/merge.html
+ version: 1.0.0
+
+x-center: &CENTER
+ x: 1
+ y: 2
+
+x-left: &LEFT
+ x: 0
+ y: 2
+
+x-big: &BIG
+ r: 10
+
+x-small: &SMALL
+ r: 1
+
+x-one:
+ <<: *CENTER
+ r: 10
+ label: center/big
+x-two:
+ <<: [*CENTER, *BIG]
+ label: center/big
+x-three:
+ <<: [*BIG, *LEFT, *SMALL]
+ x: 1
+ label: center/big
+
+paths: {}

src/__tests__/parseWithPointers.spec.ts

@@ -7,6 +7,10 @@ import { HugeYAML } from './fixtures/huge-yaml';
 
 const diverse = fs.readFileSync(path.join(__dirname, './fixtures/diverse.yaml'), 'utf-8');
 const duplicateMergeKeys = fs.readFileSync(path.join(__dirname, './fixtures/duplicate-merge-keys.yaml'), 'utf-8');
+const mergeKeysWithDuplicateProperties = fs.readFileSync(
+ path.join(__dirname, './fixtures/merge-keys-with-duplicate-props.yaml'),
+ 'utf-8'
+);
 const spectral481 = fs.readFileSync(path.join(__dirname, './fixtures/spectral-481.yaml'), 'utf-8');
 
 describe('yaml parser', () => {
@@ -428,6 +432,56 @@ european-cities: &cities
  });
  });
 
+ test('handles overrides #2', () => {
+ const result = parseWithPointers(mergeKeysWithDuplicateProperties, {
+ mergeKeys: true,
+ ignoreDuplicateKeys: false,
+ });
+
+ expect(result.data).toEqual({
+ openapi: '3.0.0',
+ 'x-format-version': '1.0',
+ info: {
+ description: 'https://yaml.org/type/merge.html',
+ title: 'Merge key issue',
+ version: '1.0.0',
+ },
+ 'x-center': {
+ x: 1,
+ y: 2,
+ },
+ 'x-left': {
+ x: 0,
+ y: 2,
+ },
+ 'x-big': {
+ r: 10,
+ },
+ 'x-small': {
+ r: 1,
+ },
+ 'x-one': {
+ x: 1,
+ y: 2,
+ r: 10,
+ label: 'center/big',
+ },
+ 'x-two': {
+ x: 1,
+ y: 2,
+ r: 10,
+ label: 'center/big',
+ },
+ 'x-three': {
+ x: 1,
+ y: 2,
+ r: 10,
+ label: 'center/big',
+ },
+ paths: {},
+ });
+ });
+
  test('handles duplicate merge keys', () => {
  const result = parseWithPointers(duplicateMergeKeys, { mergeKeys: true });
 
@@ -440,5 +494,23 @@ european-cities: &cities
  t: 4,
  });
  });
+
+ test('does not report duplicate merge keys', () => {
+ const result = parseWithPointers(duplicateMergeKeys, {
+ mergeKeys: true,
+ ignoreDuplicateKeys: false,
+ });
+
+ expect(result.diagnostics).toEqual([]);
+ });
+
+ test('does not report duplicate errors for merged keys', () => {
+ const result = parseWithPointers(mergeKeysWithDuplicateProperties, {
+ mergeKeys: true,
+ ignoreDuplicateKeys: false,
+ });
+
+ expect(result.diagnostics).toEqual([]);
+ });
  });
 });

src/parseWithPointers.ts

@@ -73,20 +73,29 @@ export const walkAST = (
  case Kind.MAP: {
  const container = {};
  // note, we don't handle null aka '~' keys on purpose
- for (const mapping of (node as YamlMap).mappings) {
- // typing is broken, value might be null
- if (mapping.key.value in container) {
- if (options !== void 0 && options.json === false) {
- throw new Error('Duplicate YAML mapping key encountered');
- }
+ const seenKeys: string[] = [];
+ const handleMergeKeys = options !== void 0 && options.mergeKeys === true;
+ const handleDuplicates = (options !== void 0 && options.json === false) || duplicatedMappingKeys !== void 0;
 
- if (duplicatedMappingKeys !== void 0) {
- duplicatedMappingKeys.push(mapping.key);
+ for (const mapping of (node as YamlMap).mappings) {
+ const key = mapping.key.value;
+
+ if (handleDuplicates && (!handleMergeKeys || key !== SpecialMappingKeys.MergeKey)) {
+ if (seenKeys.includes(mapping.key.value)) {
+ if (options !== void 0 && options.json === false) {
+ throw new Error('Duplicate YAML mapping key encountered');
+ }
+
+ if (duplicatedMappingKeys !== void 0) {
+ duplicatedMappingKeys.push(mapping.key);
+ }
+ } else {
+ seenKeys.push(key);
  }
  }
 
  // https://yaml.org/type/merge.html merge keys, not a part of YAML spec
- if (options !== void 0 && options.mergeKeys === true && mapping.key.value === SpecialMappingKeys.MergeKey) {
+ if (handleMergeKeys && key === SpecialMappingKeys.MergeKey) {
  Object.assign(container, reduceMergeKeys(walkAST(mapping.value, options, duplicatedMappingKeys)));
  } else {
  container[mapping.key.value] = walkAST(mapping.value, options, duplicatedMappingKeys);