[typescript-fetch] Add generateAnyOfAsUnion option to model anyOf as a union type

bin/configs/typescript-fetch-any-of-union.yaml

@@ -0,0 +1,9 @@
+generatorName: typescript-fetch
+outputDir: samples/client/petstore/typescript-fetch/builds/any-of-union
+inputSpec: modules/openapi-generator/src/test/resources/3_0/typescript-fetch/anyOf.yaml
+templateDir: modules/openapi-generator/src/main/resources/typescript-fetch
+additionalProperties:
+  generateAnyOfAsUnion: true
+  npmVersion: 1.0.0
+  npmName: '@openapitools/typescript-fetch-petstore'
+  npmRepository: https://skimdb.npmjs.com/registry

docs/generators/typescript-fetch.md

@@ -27,6 +27,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |enumPropertyNamingReplaceSpecialChar|Set to true to replace '-' and '+' symbols with 'minus_' and 'plus_' in enum of type string| |false|
 |enumUnknownDefaultCase|If the server adds new enum cases, that are unknown by an old spec/client, the client will fail to parse the network response. With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the server sends an enum case that is not known by the client/spec, they can safely fallback to this case.|<dl><dt>**false**</dt><dd>No changes to the enums are made, this is the default option.</dd><dt>**true**</dt><dd>With this option enabled, each enum will have a new case, 'unknown_default_open_api', so that when the enum case sent by the server is not known by the client/spec, can safely be decoded to this case.</dd></dl>|false|
 |fileNaming|Naming convention for the output files: 'PascalCase', 'camelCase', 'kebab-case'.| |PascalCase|
+|generateAnyOfAsUnion|Generate anyOf schemas as TypeScript union types instead of one interface merging all members' properties. A value matching several object members keeps the properties of all of them. An anyOf schema that also declares its own properties stays an interface.| |false|
 |importFileExtension|File extension to use with relative imports. Set it to '.js' or '.mjs' when using [ESM](https://nodejs.org/api/esm.html).| ||
 |legacyDiscriminatorBehavior|Set to false for generators with better support for discriminators. (Python, Java, Go, PowerShell, C# have this enabled by default).|<dl><dt>**true**</dt><dd>The mapping in the discriminator includes descendent schemas that allOf inherit from self and the discriminator mapping schemas in the OAS document.</dd><dt>**false**</dt><dd>The mapping in the discriminator includes any descendent schemas that allOf inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values, and the discriminator mapping schemas in the OAS document AND Codegen validates that oneOf and anyOf schemas contain the required discriminator and throws an error if the discriminator is missing.</dd></dl>|true|
 |licenseName|The name of the license| |null|

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java

@@ -73,6 +73,8 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
     public static final String DATE_LIBRARY_DATE = "date";
     public static final String DATE_LIBRARY_STRING = "string";
     public static final String DATE_LIBRARY_TEMPORAL = "temporal";
+    public static final String GENERATE_ANY_OF_AS_UNION = "generateAnyOfAsUnion";
+    public static final String GENERATE_ANY_OF_AS_UNION_DESC = "Generate anyOf schemas as TypeScript union types instead of one interface merging all members' properties. A value matching several object members keeps the properties of all of them. An anyOf schema that also declares its own properties stays an interface.";
     public static final String STRING_ENUMS = "stringEnums";
     public static final String STRING_ENUMS_DESC = "Generate string enums instead of objects for enum values.";
     public static final String IMPORT_FILE_EXTENSION_SWITCH = "importFileExtension";
@@ -96,6 +98,7 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
     protected boolean addedModelIndex = false;
     protected boolean withoutRuntimeChecks = false;
     protected String dateLibrary = DATE_LIBRARY_DATE;
+    protected boolean generateAnyOfAsUnion = false;
     protected boolean stringEnums = false;
     protected String fileNaming = PASCAL_CASE;
     protected String apiDocPath = "docs";
@@ -171,6 +174,7 @@ public TypeScriptFetchClientCodegen() {
         dateLibraryOption.setEnum(dateOptions);
         this.cliOptions.add(dateLibraryOption);
         this.cliOptions.add(new CliOption(SAGAS_AND_RECORDS, "Setting this property to true will generate additional files for use with redux-saga and immutablejs.", SchemaTypeUtil.BOOLEAN_TYPE).defaultValue(Boolean.FALSE.toString()));
+        this.cliOptions.add(new CliOption(GENERATE_ANY_OF_AS_UNION, GENERATE_ANY_OF_AS_UNION_DESC, SchemaTypeUtil.BOOLEAN_TYPE).defaultValue(Boolean.FALSE.toString()));
         this.cliOptions.add(new CliOption(STRING_ENUMS, STRING_ENUMS_DESC, SchemaTypeUtil.BOOLEAN_TYPE).defaultValue(Boolean.FALSE.toString()));
         this.cliOptions.add(new CliOption(IMPORT_FILE_EXTENSION_SWITCH, IMPORT_FILE_EXTENSION_SWITCH_DESC).defaultValue(""));
         this.cliOptions.add(new CliOption(FILE_NAMING, "Naming convention for the output files: 'PascalCase', 'camelCase', 'kebab-case'.").defaultValue(this.fileNaming));
@@ -236,6 +240,14 @@ public void setDateLibrary(String dateLibrary) {
         this.dateLibrary = dateLibrary;
     }
 
+    public Boolean getGenerateAnyOfAsUnion() {
+        return this.generateAnyOfAsUnion;
+    }
+
+    public void setGenerateAnyOfAsUnion(Boolean generateAnyOfAsUnion) {
+        this.generateAnyOfAsUnion = generateAnyOfAsUnion;
+    }
+
     public Boolean getStringEnums() {
         return this.stringEnums;
     }
@@ -344,6 +356,10 @@ public void processOpts() {
             this.setWithoutRuntimeChecks(convertPropertyToBoolean(WITHOUT_RUNTIME_CHECKS));
         }
 
+        if (additionalProperties.containsKey(GENERATE_ANY_OF_AS_UNION)) {
+            this.setGenerateAnyOfAsUnion(convertPropertyToBoolean(GENERATE_ANY_OF_AS_UNION));
+        }
+
         if (additionalProperties.containsKey(STRING_ENUMS)) {
             this.setStringEnums(convertPropertyToBoolean(STRING_ENUMS));
             additionalProperties.put("stringEnums", this.stringEnums);
@@ -604,6 +620,22 @@ public Map<String, ModelsMap> postProcessAllModels(Map<String, ModelsMap> objs)
             }
         }
 
+        // Split the oneOf/anyOf model members: the instanceOf check of an enum takes the primitive value itself,
+        // while the one of an object model needs an object.
+        Set<String> enumModelNames = allModels.stream()
+                .filter(m -> m.isEnum)
+                .map(m -> m.classname)
+                .collect(Collectors.toSet());
+        for (ExtendedCodegenModel m : allModels) {
+            for (String member : m.oneOfModels) {
+                if (enumModelNames.contains(member)) {
+                    m.oneOfEnumModels.add(member);
+                } else {
+                    m.oneOfObjectModels.add(member);
+                }
+            }
+        }
+
         for (ExtendedCodegenModel rootModel : allModels) {
             for (String curImport : rootModel.imports) {
                 boolean isModelImport = false;
@@ -834,7 +866,11 @@ public ExtendedCodegenProperty fromProperty(String name, Schema p, boolean requi
     @Override
     public ExtendedCodegenModel fromModel(String name, Schema model) {
         CodegenModel cm = super.fromModel(name, model);
-        return new ExtendedCodegenModel(cm);
+        ExtendedCodegenModel result = new ExtendedCodegenModel(cm);
+        // The union template renders no properties, so an anyOf declaring its own properties stays an interface.
+        result.anyOfHasOwnProperties = model.getAnyOf() != null && !model.getAnyOf().isEmpty()
+                && model.getProperties() != null && !model.getProperties().isEmpty();
+        return result;
     }
 
     @Override
@@ -1081,8 +1117,20 @@ private ExtendedCodegenModel processCodeGenModel(ExtendedCodegenModel cm) {
                 .map(CodegenComposedSchemas::getOneOf)
                 .orElse(Collections.emptyList());
 
-        // Type names omit branch nullability. Null is valid only when exactly one branch accepts it.
-        if (oneOfsList.stream().filter(cp -> cp.isNullable).count() == 1) {
+        // With generateAnyOfAsUnion an anyOf is modeled like a oneOf, so the oneOf templates render it as a union.
+        boolean fromAnyOf = this.generateAnyOfAsUnion && cm.oneOf.isEmpty() && !cm.anyOf.isEmpty() && !cm.anyOfHasOwnProperties;
+        if (fromAnyOf) {
+            oneOfsList = Optional.ofNullable(cm.getComposedSchemas())
+                    .map(CodegenComposedSchemas::getAnyOf)
+                    .orElse(Collections.emptyList());
+            cm.oneOf.addAll(cm.anyOf);
+            cm.isAnyOfUnion = true;
+        }
+
+        // Type names omit branch nullability. For oneOf, null is valid only when exactly one branch accepts it;
+        // for anyOf, when at least one branch does.
+        long nullableBranches = oneOfsList.stream().filter(cp -> cp.isNullable).count();
+        if (fromAnyOf ? nullableBranches >= 1 : nullableBranches == 1) {
             cm.oneOf.add("null");
         }
 
@@ -2107,6 +2155,9 @@ public class ExtendedCodegenModel extends CodegenModel {
         // 'TypedJSON' conversion methods in the composed model classes.
         @Getter @Setter
         public Set<String> oneOfModels = new TreeSet<>();
+        // oneOfModels split by kind, see postProcessAllModels
+        public Set<String> oneOfObjectModels = new TreeSet<>();
+        public Set<String> oneOfEnumModels = new TreeSet<>();
         @Getter @Setter
         public Set<String> oneOfArrays = new TreeSet<>();
         @Getter @Setter
@@ -2115,6 +2166,9 @@ public class ExtendedCodegenModel extends CodegenModel {
         public CodegenDiscriminator.MappedModel selfReferencingDiscriminatorMapping;
         @Getter @Setter
         public boolean parentIsOneOf; // true when this model's parent is a oneOf union type
+        @Getter @Setter
+        public boolean isAnyOfUnion; // true when an anyOf is generated as a union type (generateAnyOfAsUnion)
+        public boolean anyOfHasOwnProperties; // true when an anyOf schema declares properties next to its members
 
         public boolean isEntity; // Is a model containing an "id" property marked as isUniqueId
         public String returnPassthrough;

modules/openapi-generator/src/main/resources/typescript-fetch/modelOneOf.mustache

@@ -44,20 +44,44 @@ export function {{classname}}FromJSONTyped(json: any, ignoreDiscriminator: boole
     }
 {{/discriminator}}
 {{^discriminator}}
-    {{#oneOfModels}}
+    {{#oneOfObjectModels}}
     {{#-first}}
-    if (typeof json !== 'object') {
-        return json;
-    }
+    if (typeof json === 'object') {
+    {{#isAnyOfUnion}}
+        // anyOf: a value may match several members, so combine all of them instead of keeping the first match
+        let anyOfResult: any = {};
+        let anyOfMatched = false;
+    {{/isAnyOfUnion}}
     {{/-first}}
+    {{#isAnyOfUnion}}
+        if (instanceOf{{{.}}}(json)) {
+            anyOfResult = { ...anyOfResult, ...{{{.}}}FromJSONTyped(json, true) };
+            anyOfMatched = true;
+        }
+    {{/isAnyOfUnion}}
+    {{^isAnyOfUnion}}
+        if (instanceOf{{{.}}}(json)) {
+            return {{{.}}}FromJSONTyped(json, true);
+        }
+    {{/isAnyOfUnion}}
+    {{#-last}}
+    {{#isAnyOfUnion}}
+        if (anyOfMatched) {
+            return anyOfResult;
+        }
+    {{/isAnyOfUnion}}
+    }
+    {{/-last}}
+    {{/oneOfObjectModels}}
+    {{#oneOfEnumModels}}
     if (instanceOf{{{.}}}(json)) {
         return {{{.}}}FromJSONTyped(json, true);
     }
-    {{/oneOfModels}}
+    {{/oneOfEnumModels}}
     {{#oneOfArrays}}
     {{#-first}}
     if (Array.isArray(json)) {
-        if (json.every(item => typeof item === 'object')) {
+        if (json.every(item => item !== null && typeof item === 'object')) {
     {{/-first}}
             if (json.every(item => instanceOf{{{.}}}(item))) {
                 return json.map(value => {{{.}}}FromJSONTyped(value, true));
@@ -197,20 +221,44 @@ export function {{classname}}ToJSONTyped(value?: {{classname}} | null, ignoreDis
     }
 {{/discriminator}}
 {{^discriminator}}
-    {{#oneOfModels}}
+    {{#oneOfObjectModels}}
     {{#-first}}
-    if (typeof value !== 'object') {
-        return value;
-    }
+    if (typeof value === 'object') {
+    {{#isAnyOfUnion}}
+        // anyOf: a value may match several members, so combine all of them instead of keeping the first match
+        let anyOfResult: any = {};
+        let anyOfMatched = false;
+    {{/isAnyOfUnion}}
     {{/-first}}
+    {{#isAnyOfUnion}}
+        if (instanceOf{{{.}}}(value)) {
+            anyOfResult = { ...anyOfResult, ...{{{.}}}ToJSON(value as {{{.}}}) };
+            anyOfMatched = true;
+        }
+    {{/isAnyOfUnion}}
+    {{^isAnyOfUnion}}
+        if (instanceOf{{{.}}}(value)) {
+            return {{{.}}}ToJSON(value as {{{.}}});
+        }
+    {{/isAnyOfUnion}}
+    {{#-last}}
+    {{#isAnyOfUnion}}
+        if (anyOfMatched) {
+            return anyOfResult;
+        }
+    {{/isAnyOfUnion}}
+    }
+    {{/-last}}
+    {{/oneOfObjectModels}}
+    {{#oneOfEnumModels}}
     if (instanceOf{{{.}}}(value)) {
         return {{{.}}}ToJSON(value as {{{.}}});
     }
-    {{/oneOfModels}}
+    {{/oneOfEnumModels}}
     {{#oneOfArrays}}
     {{#-first}}
     if (Array.isArray(value)) {
-        if (value.every(item => typeof item === 'object')) {
+        if (value.every(item => item !== null && typeof item === 'object')) {
     {{/-first}}
             if (value.every(item => instanceOf{{{.}}}(item))) {
                 return value.map(value => {{{.}}}ToJSON(value as {{{.}}}));

modules/openapi-generator/src/test/java/org/openapitools/codegen/options/TypeScriptFetchClientOptionsProvider.java

@@ -30,6 +30,7 @@ public class TypeScriptFetchClientOptionsProvider implements TypeScriptSharedCli
     private static final String NPM_REPOSITORY = "https://registry.npmjs.org";
     public static final String SAGAS_AND_RECORDS = "false";
     public static final String STRING_ENUMS = "false";
+    public static final String GENERATE_ANY_OF_AS_UNION = "false";
     public static final String FILE_NAMING_VALUE = PASCAL_CASE;
     public static final String DATE_LIBRARY_VALUE = TypeScriptFetchClientCodegen.DATE_LIBRARY_STRING;
 
@@ -53,6 +54,7 @@ public Map<String, String> createOptions() {
                 .put(TypeScriptFetchClientCodegen.FILE_NAMING, FILE_NAMING_VALUE)
                 .put(TypeScriptFetchClientCodegen.DATE_LIBRARY, DATE_LIBRARY_VALUE)
                 .put(TypeScriptFetchClientCodegen.STRING_ENUMS, STRING_ENUMS)
+                .put(TypeScriptFetchClientCodegen.GENERATE_ANY_OF_AS_UNION, GENERATE_ANY_OF_AS_UNION)
                 .put(TypeScriptFetchClientCodegen.USE_SQUARE_BRACKETS_IN_ARRAY_NAMES, Boolean.FALSE.toString())
                 .put(TypeScriptFetchClientCodegen.VALIDATION_ATTRIBUTES, Boolean.FALSE.toString())
                 .put(TypeScriptFetchClientCodegen.WITH_REQUEST_OPTS_IN_INTERFACE, Boolean.TRUE.toString())