make types nullable

src/generator.ts

@@ -186,23 +186,23 @@ function generateRawType(ast: AST, options: Options): string {
         return type.endsWith('"') ? '(' + type + ')[]' : type + '[]'
       })()
     case 'BOOLEAN':
-      return 'boolean'
+      return 'boolean' + (ast.isNullable ? ' | null' : '')
     case 'INTERFACE':
       return generateInterface(ast, options)
     case 'INTERSECTION':
       return generateSetOperation(ast, options)
     case 'LITERAL':
       return JSON.stringify(ast.params)
     case 'NUMBER':
-      return 'number'
+      return 'number' + (ast.isNullable ? ' | null' : '')
     case 'NULL':
       return 'null'
     case 'OBJECT':
-      return 'object'
+      return 'object' + (ast.isNullable ? ' | null' : '')
     case 'REFERENCE':
       return ast.params
     case 'STRING':
-      return 'string'
+      return 'string' + (ast.isNullable ? ' | null' : '')
     case 'TUPLE':
       return (() => {
         const minItems = ast.minItems
@@ -284,7 +284,7 @@ function generateRawType(ast: AST, options: Options): string {
     case 'UNION':
       return generateSetOperation(ast, options)
     case 'CUSTOM_TYPE':
-      return ast.params
+      return ast.params + (ast.isNullable ? ' | null' : '')
   }
 }
 
@@ -293,6 +293,9 @@ function generateRawType(ast: AST, options: Options): string {
  */
 function generateSetOperation(ast: TIntersection | TUnion, options: Options): string {
   const members = (ast as TUnion).params.map(_ => generateType(_, options))
+  if (ast.type === 'UNION' && ast.isNullable) {
+    members.push('null')
+  }
   const separator = ast.type === 'UNION' ? '|' : '&'
   return members.length === 1 ? members[0] : '(' + members.join(' ' + separator + ' ') + ')'
 }

src/parser.ts

@@ -104,6 +104,7 @@ function parseNonLiteral(
     case 'ANY_OF':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         params: schema.anyOf!.map(_ => parse(_, options, rootSchema, undefined, true, processed, usedNames)),
         standaloneName: standaloneName(schema, keyNameFromDefinition, usedNames),
@@ -112,13 +113,15 @@ function parseNonLiteral(
     case 'BOOLEAN':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         standaloneName: standaloneName(schema, keyNameFromDefinition, usedNames),
         type: 'BOOLEAN'
       })
     case 'CUSTOM_TYPE':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         params: schema.tsType!,
         standaloneName: standaloneName(schema, keyNameFromDefinition, usedNames),
@@ -147,20 +150,23 @@ function parseNonLiteral(
     case 'NUMBER':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         standaloneName: standaloneName(schema, keyNameFromDefinition, usedNames),
         type: 'NUMBER'
       })
     case 'OBJECT':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         standaloneName: standaloneName(schema, keyNameFromDefinition, usedNames),
         type: 'OBJECT'
       })
     case 'ONE_OF':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         params: schema.oneOf!.map(_ => parse(_, options, rootSchema, undefined, true, processed, usedNames)),
         standaloneName: standaloneName(schema, keyNameFromDefinition, usedNames),
@@ -171,6 +177,7 @@ function parseNonLiteral(
     case 'STRING':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         standaloneName: standaloneName(schema, keyNameFromDefinition, usedNames),
         type: 'STRING'
@@ -218,6 +225,7 @@ function parseNonLiteral(
     case 'UNION':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         params: (schema.type as JSONSchema4TypeName[]).map(_ =>
           parse({...schema, type: _}, options, rootSchema, undefined, true, processed, usedNames)
@@ -228,6 +236,7 @@ function parseNonLiteral(
     case 'UNNAMED_ENUM':
       return set({
         comment: schema.description,
+        isNullable: !!schema.nullable,
         keyName,
         params: schema.enum!.map(_ => parse(_, options, rootSchema, undefined, false, processed, usedNames)),
         standaloneName: standaloneName(schema, keyNameFromDefinition, usedNames),

src/types/AST.ts

@@ -37,6 +37,7 @@ export interface TArray extends AbstractAST {
 }
 
 export interface TBoolean extends AbstractAST {
+  isNullable: boolean
   type: 'BOOLEAN'
 }
 
@@ -83,6 +84,7 @@ export interface TLiteral extends AbstractAST {
 }
 
 export interface TNumber extends AbstractAST {
+  isNullable: boolean
   type: 'NUMBER'
 }
 
@@ -91,6 +93,7 @@ export interface TNull extends AbstractAST {
 }
 
 export interface TObject extends AbstractAST {
+  isNullable: boolean
   type: 'OBJECT'
 }
 
@@ -100,6 +103,7 @@ export interface TReference extends AbstractAST {
 }
 
 export interface TString extends AbstractAST {
+  isNullable: boolean
   type: 'STRING'
 }
 
@@ -112,11 +116,13 @@ export interface TTuple extends AbstractAST {
 }
 
 export interface TUnion extends AbstractAST {
+  isNullable: boolean
   type: 'UNION'
   params: AST[]
 }
 
 export interface TCustomType extends AbstractAST {
+  isNullable: boolean
   type: 'CUSTOM_TYPE'
   params: string
 }