Add option for sorting union members

README.md

@@ -140,6 +140,10 @@ If set to true, string enums and unions will be converted to docgen enum format.
 
 If set to true, every unions will be converted to docgen enum format.
 
+### `shouldSortUnions`: boolean
+
+When used in combination with `shouldExtractValuesFromUnion` or `shouldExtractLiteralValuesFromEnum`, sorts union members in string-sort order when set to true. This is useful for ensuring the same order of members every time.
+
 ### `skipChildrenPropWithoutDoc`: boolean (default: `true`)
 
 If set to false the docs for the `children` prop will be generated even without an explicit description.

src/__tests__/data/SimpleUnions.tsx

@@ -0,0 +1,8 @@
+type SampleUnion = 'h1' | 'h6' | 'h2' | 'h4' | 'h5' | 'h3';
+
+interface Props {
+  /** sampleUnionProp description */
+  sampleUnionProp: SampleUnion;
+}
+
+export const SimpleUnions = (props: Props) => <div />;

src/__tests__/parser.ts

@@ -1448,6 +1448,63 @@ describe('parser', () => {
       });
     });
 
+    describe('Sorting unions', () => {
+      it('does not sort union members by default', () => {
+        check(
+          'SimpleUnions',
+          {
+            SimpleUnions: {
+              sampleUnionProp: {
+                raw: 'SampleUnion',
+                type: 'enum',
+                value: [
+                  { value: '"h1"' },
+                  { value: '"h6"' },
+                  { value: '"h2"' },
+                  { value: '"h4"' },
+                  { value: '"h5"' },
+                  { value: '"h3"' }
+                ]
+              }
+            }
+          },
+          false,
+          null,
+          {
+            shouldExtractLiteralValuesFromEnum: true
+          }
+        );
+      });
+
+      it('sorts union members when shouldSortUnions is true', () => {
+        check(
+          'SimpleUnions',
+          {
+            SimpleUnions: {
+              sampleUnionProp: {
+                raw: 'SampleUnion',
+                type: 'enum',
+                value: [
+                  { value: '"h1"' },
+                  { value: '"h2"' },
+                  { value: '"h3"' },
+                  { value: '"h4"' },
+                  { value: '"h5"' },
+                  { value: '"h6"' }
+                ]
+              }
+            }
+          },
+          false,
+          null,
+          {
+            shouldExtractLiteralValuesFromEnum: true,
+            shouldSortUnions: true
+          }
+        );
+      });
+    });
+
     describe('Returning not string default props ', () => {
       it('returns not string defaultProps', () => {
         check(

src/parser.ts

@@ -87,6 +87,7 @@ export interface ParserOptions {
   shouldExtractLiteralValuesFromEnum?: boolean;
   shouldRemoveUndefinedFromOptional?: boolean;
   shouldExtractValuesFromUnion?: boolean;
+  shouldSortUnions?: boolean;
   skipChildrenPropWithoutDoc?: boolean;
   savePropValueAsString?: boolean;
   shouldIncludePropTagMap?: boolean;
@@ -220,6 +221,7 @@ export class Parser {
   private readonly shouldRemoveUndefinedFromOptional: boolean;
   private readonly shouldExtractLiteralValuesFromEnum: boolean;
   private readonly shouldExtractValuesFromUnion: boolean;
+  private readonly shouldSortUnions: boolean;
   private readonly savePropValueAsString: boolean;
   private readonly shouldIncludePropTagMap: boolean;
   private readonly shouldIncludeExpression: boolean;
@@ -230,6 +232,7 @@ export class Parser {
       shouldExtractLiteralValuesFromEnum,
       shouldRemoveUndefinedFromOptional,
       shouldExtractValuesFromUnion,
+      shouldSortUnions,
       shouldIncludePropTagMap,
       shouldIncludeExpression
     } = opts;
@@ -242,6 +245,7 @@ export class Parser {
       shouldRemoveUndefinedFromOptional
     );
     this.shouldExtractValuesFromUnion = Boolean(shouldExtractValuesFromUnion);
+    this.shouldSortUnions = Boolean(shouldSortUnions);
     this.savePropValueAsString = Boolean(savePropValueAsString);
     this.shouldIncludePropTagMap = Boolean(shouldIncludePropTagMap);
     this.shouldIncludeExpression = Boolean(shouldIncludeExpression);
@@ -635,6 +639,12 @@ export class Parser {
           value = value.filter(option => option.value != 'undefined');
         }
 
+        if (this.shouldSortUnions) {
+          value.sort((a, b) =>
+            a.value.toString().localeCompare(b.value.toString())
+          );
+        }
+
         return {
           name: 'enum',
           raw: propTypeString,