style: make use of tagged union literals (#28)

* build: use tslint-config-stoplight

* style: make use of tagged union literals

* style: commas

package.json

@@ -28,7 +28,7 @@
   "scripts": {
     "build": "sl-scripts build",
     "commit": "git-cz",
-    "lint": "tslint -c tslint.json 'src/**/*.ts'",
+    "lint": "tslint -c tslint.json -p tsconfig.json 'src/**/*.ts'",
     "lint.fix": "yarn lint --fix",
     "release": "sl-scripts release",
     "release.docs": "sl-scripts release:docs",
@@ -45,6 +45,7 @@
   },
   "devDependencies": {
     "@stoplight/scripts": "3.1.0",
+    "tslint-config-stoplight": "^1.3.0",
     "typescript": "3.5.3"
   },
   "lint-staged": {

src/__tests__/getLocationForJsonPath.spec.ts

@@ -49,7 +49,7 @@ describe('getLocationForJsonPath', () => {
                 },
               },
             }
-          : void 0
+          : void 0,
       );
     });
   });
@@ -104,7 +104,7 @@ describe('getLocationForJsonPath', () => {
   describe('duplicate keys fixture', () => {
     const result = parseWithPointers(
       `foo: 2
-foo: 4`
+foo: 4`,
     );
 
     test.each`
@@ -164,7 +164,7 @@ foo: 4`
   << : [ *BIG, *LEFT, *SMALL ]
   x: 1
   label: center/big`,
-      { mergeKeys: true }
+      { mergeKeys: true },
     );
 
     test.each`
@@ -193,7 +193,7 @@ foo: 4`
 
     test('should return proper location for empty mapping value', () => {
       expect(
-        getLocationForJsonPath(result, ['definitions', 'AnotherDefinition', 'properties', 'special', 'description'])
+        getLocationForJsonPath(result, ['definitions', 'AnotherDefinition', 'properties', 'special', 'description']),
       ).toEqual({
         range: {
           start: {
@@ -223,7 +223,7 @@ foo: 4`
       ${[5, 6]} | ${[5, 9]}  | ${['paths']}           | ${true}
     `('should return proper location for given JSONPath $path', ({ start, end, path, closest }) => {
       expect(getLocationForJsonPath(resultCRLF, path, closest)).toEqual(
-        getLocationForJsonPath(resultLF, path, closest)
+        getLocationForJsonPath(resultLF, path, closest),
       );
       expect(getLocationForJsonPath(resultCRLF, path)).toEqual(getLocationForJsonPath(resultLF, path));
       expect(getLocationForJsonPath(resultCRLF, path, closest)).toEqual(
@@ -240,7 +240,7 @@ foo: 4`
                 },
               },
             }
-          : void 0
+          : void 0,
       );
     });
   });
@@ -266,7 +266,7 @@ foo: 4`
                 },
               },
             }
-          : void 0
+          : void 0,
       );
     });
   });

src/__tests__/parseWithPointers.spec.ts

@@ -9,7 +9,7 @@ const diverse = fs.readFileSync(path.join(__dirname, './fixtures/diverse.yaml'),
 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'
+  'utf-8',
 );
 const spectral481 = fs.readFileSync(path.join(__dirname, './fixtures/spectral-481.yaml'), 'utf-8');
 
@@ -38,15 +38,15 @@ describe('yaml parser', () => {
     const { data } = parseWithPointers(spectral481);
     expect(data).toHaveProperty(
       'components.schemas.RandomRequest.properties.implicit_string_date.example',
-      '2012-10-12'
+      '2012-10-12',
     );
     expect(data).toHaveProperty(
       'components.schemas.RandomRequest.properties.another_implicit_string_date.example',
-      'x20121012'
+      'x20121012',
     );
     expect(data).toHaveProperty(
       'components.schemas.RandomRequest.properties.explicit_string_date.example',
-      '2012-10-12'
+      '2012-10-12',
     );
   });
 
@@ -100,7 +100,7 @@ test: !!css >
         `prop1: true
 prop2: true
   inner 1
-  val: 2`
+  val: 2`,
       );
 
       expect(result.diagnostics).toEqual([
@@ -267,7 +267,7 @@ european-cities: &cities
 
     test('throws when duplicate key is encountered and not in JSON-ish mode', () => {
       expect(parseWithPointers.bind(null, 'foo: 0\nfoo: 1\n', { json: false })).toThrow(
-        'Duplicate YAML mapping key encountered'
+        'Duplicate YAML mapping key encountered',
       );
     });
 
@@ -301,8 +301,8 @@ european-cities: &cities
     - yes
     - unfortunately, I am a dupe.
 `,
-          { ignoreDuplicateKeys: false }
-        )
+          { ignoreDuplicateKeys: false },
+        ),
       ).toHaveProperty('diagnostics', [
         {
           code: 'YAMLException',
@@ -354,7 +354,7 @@ european-cities: &cities
   << : *CENTER
   r: 10
   label: center/big`,
-        { mergeKeys: true }
+        { mergeKeys: true },
       );
 
       expect(result.data![4]).toEqual({
@@ -376,7 +376,7 @@ european-cities: &cities
 - # Merge multiple maps
   << : [ *CENTER, *BIG ]
   label: center/big`,
-        { mergeKeys: true }
+        { mergeKeys: true },
       );
 
       expect(result.data![4]).toEqual({
@@ -398,7 +398,7 @@ european-cities: &cities
 - # Merge multiple maps
   << : [ *CENTER, *BIG ]
   label: center/big`,
-        { mergeKeys: true }
+        { mergeKeys: true },
       );
 
       expect(result.data![4]).toEqual({
@@ -421,7 +421,7 @@ european-cities: &cities
   << : [ *BIG, *LEFT, *SMALL ]
   x: 1
   label: center/big`,
-        { mergeKeys: true }
+        { mergeKeys: true },
       );
 
       expect(result.data![4]).toEqual({

src/buildJsonPath.ts

@@ -1,5 +1,5 @@
 import { JsonPath } from '@stoplight/types';
-import { Kind, YAMLMapping, YAMLNode, YAMLScalar, YAMLSequence } from '@stoplight/yaml-ast-parser';
+import { Kind, YAMLNode } from './types';
 import { isObject } from './utils';
 
 export function buildJsonPath(node: YAMLNode) {
@@ -10,20 +10,20 @@ export function buildJsonPath(node: YAMLNode) {
   while (node) {
     switch (node.kind) {
       case Kind.SCALAR:
-        path.unshift((node as YAMLScalar).value);
+        path.unshift(node.value);
         break;
       case Kind.MAPPING:
-        if (prevNode !== (node as YAMLMapping).key) {
-          if (path.length > 0 && isObject(node.value) && (node as YAMLMapping).value.value === path[0]) {
-            path[0] = (node as YAMLMapping).key.value;
+        if (prevNode !== node.key) {
+          if (path.length > 0 && isObject(node.value) && node.value.value === path[0]) {
+            path[0] = node.key.value;
           } else {
-            path.unshift((node as YAMLMapping).key.value);
+            path.unshift(node.key.value);
           }
         }
         break;
       case Kind.SEQ:
         if (prevNode) {
-          const index = (node as YAMLSequence).items.indexOf(prevNode);
+          const index = node.items.indexOf(prevNode);
           if (prevNode.kind === Kind.SCALAR) {
             path[0] = index;
             // always better to point to parent node rather than nothing

src/getJsonPathForPosition.ts

@@ -1,12 +1,11 @@
 import { GetJsonPathForPosition } from '@stoplight/types';
-import { Kind, YAMLMapping, YAMLNode, YAMLSequence } from '@stoplight/yaml-ast-parser';
 import { buildJsonPath } from './buildJsonPath';
-import { YamlParserResult } from './types';
+import { Kind, YAMLNode, YamlParserResult } from './types';
 import { isObject } from './utils';
 
 export const getJsonPathForPosition: GetJsonPathForPosition<YamlParserResult<unknown>> = (
   { ast, lineMap },
-  { line, character }
+  { line, character },
 ) => {
   if (line >= lineMap.length || character >= lineMap[line]) {
     return;
@@ -15,7 +14,7 @@ export const getJsonPathForPosition: GetJsonPathForPosition<YamlParserResult<unk
   const startOffset = line === 0 ? 0 : lineMap[line - 1] + 1;
 
   const node = findClosestScalar(ast, Math.min(lineMap[line] - 1, startOffset + character), line, lineMap);
-  if (!node) return;
+  if (!isObject(node)) return;
 
   const path = buildJsonPath(node);
   if (path.length === 0) return;
@@ -36,17 +35,17 @@ function* walk(node: YAMLNode): IterableIterator<YAMLNode> {
       break;
     case Kind.MAPPING:
       if (isObject(node.key)) {
-        yield (node as YAMLMapping).key;
+        yield node.key;
       }
 
       if (isObject(node.value)) {
-        yield (node as YAMLMapping).value;
+        yield node.value;
       }
 
       break;
     case Kind.SEQ:
-      if ((node as YAMLSequence).items.length !== 0) {
-        for (const item of (node as YAMLSequence).items) {
+      if (node.items.length !== 0) {
+        for (const item of node.items) {
           if (isObject(item)) {
             yield item;
           }
@@ -66,7 +65,7 @@ function getFirstScalarChild(node: YAMLNode, line: number, lineMap: number[]): Y
 
   switch (node.kind) {
     case Kind.MAPPING:
-      return (node as YAMLMapping).key;
+      return node.key;
     case Kind.MAP:
       if (node.mappings.length !== 0) {
         for (const mapping of node.mappings) {
@@ -78,8 +77,8 @@ function getFirstScalarChild(node: YAMLNode, line: number, lineMap: number[]): Y
 
       break;
     case Kind.SEQ:
-      if ((node as YAMLSequence).items.length !== 0) {
-        for (const item of (node as YAMLSequence).items) {
+      if (node.items.length !== 0) {
+        for (const item of node.items) {
           if (item.startPosition > startOffset && item.startPosition <= endOffset) {
             return getFirstScalarChild(item, line, lineMap);
           }
@@ -109,8 +108,8 @@ function findClosestScalar(container: YAMLNode, offset: number, line: number, li
       return getFirstScalarChild(container, line, lineMap);
     }
 
-    if ((container as YAMLMapping).value && (container as YAMLMapping).key.endPosition < offset) {
-      return getFirstScalarChild((container as YAMLMapping).value, line, lineMap);
+    if (container.value && container.key.endPosition < offset) {
+      return getFirstScalarChild(container.value, line, lineMap);
     }
   }
 

src/getLocationForJsonPath.ts

@@ -1,14 +1,13 @@
-import { GetLocationForJsonPath, ILocation, JsonPath } from '@stoplight/types';
-import { Kind, YAMLMapping, YAMLNode, YAMLSequence } from '@stoplight/yaml-ast-parser';
+import { GetLocationForJsonPath, ILocation, JsonPath, Optional } from '@stoplight/types';
 import { SpecialMappingKeys } from './consts';
 import { lineForPosition } from './lineForPosition';
-import { YamlParserResult } from './types';
+import { Kind, YAMLMapping, YAMLNode, YamlParserResult } from './types';
 import { isObject } from './utils';
 
 export const getLocationForJsonPath: GetLocationForJsonPath<YamlParserResult<unknown>> = (
   { ast, lineMap, metadata },
   path,
-  closest = false
+  closest = false,
 ) => {
   const node = findNodeAtPath(ast, path, { closest, mergeKeys: metadata !== undefined && metadata.mergeKeys === true });
   if (node === void 0) return;
@@ -41,7 +40,7 @@ function getStartPosition(node: YAMLNode, offset: number): number {
 function getEndPosition(node: YAMLNode): number {
   switch (node.kind) {
     case Kind.SEQ:
-      const { items } = node as YAMLSequence;
+      const { items } = node;
       if (items.length !== 0 && items[items.length - 1] !== null) {
         return getEndPosition(items[items.length - 1]);
       }
@@ -72,10 +71,14 @@ function getEndPosition(node: YAMLNode): number {
 function findNodeAtPath(
   node: YAMLNode,
   path: JsonPath,
-  { closest, mergeKeys }: { closest: boolean; mergeKeys: boolean }
+  { closest, mergeKeys }: { closest: boolean; mergeKeys: boolean },
 ) {
   pathLoop: for (const segment of path) {
-    switch (node && node.kind) {
+    if (!isObject(node)) {
+      return closest ? node : void 0;
+    }
+
+    switch (node.kind) {
       case Kind.MAP:
         const mappings = getMappings(node.mappings, mergeKeys);
         // we iterate from the last to first to be compliant with JSONish mode
@@ -94,9 +97,9 @@ function findNodeAtPath(
 
         return closest ? node : void 0;
       case Kind.SEQ:
-        for (let i = 0; i < (node as YAMLSequence).items.length; i++) {
+        for (let i = 0; i < node.items.length; i++) {
           if (i === Number(segment)) {
-            node = (node as YAMLSequence).items[i];
+            node = node.items[i];
             continue pathLoop;
           }
         }
@@ -116,7 +119,7 @@ function getMappings(mappings: YAMLMapping[], mergeKeys: boolean): YAMLMapping[]
   return mappings.reduce<YAMLMapping[]>((mergedMappings, mapping) => {
     if (isObject(mapping)) {
       if (mapping.key.value === SpecialMappingKeys.MergeKey) {
-        mergedMappings.push(...reduceMergeKeys((mapping as YAMLMapping).value));
+        mergedMappings.push(...reduceMergeKeys(mapping.value));
       } else {
         mergedMappings.push(mapping);
       }
@@ -126,10 +129,12 @@ function getMappings(mappings: YAMLMapping[], mergeKeys: boolean): YAMLMapping[]
   }, []);
 }
 
-function reduceMergeKeys(node: YAMLNode): YAMLMapping[] {
+function reduceMergeKeys(node: Optional<YAMLNode | null>): YAMLMapping[] {
+  if (!isObject(node)) return [];
+
   switch (node.kind) {
     case Kind.SEQ:
-      return (node as YAMLSequence).items.reduceRight<YAMLMapping[]>((items, item) => {
+      return node.items.reduceRight<YAMLMapping[]>((items, item) => {
         items.push(...reduceMergeKeys(item));
         return items;
       }, []);

src/parse.ts

@@ -1,4 +1,5 @@
 import { load as loadAST } from '@stoplight/yaml-ast-parser';
 import { walkAST } from './parseWithPointers';
+import { YAMLNode } from './types';
 
-export const parse = <T>(value: string): T => walkAST(loadAST(value)) as T;
+export const parse = <T>(value: string): T => walkAST(loadAST(value) as YAMLNode) as T;