[typescript] make TypeScript version configurable (#20064)

Author: Dennis Ameling

docs/generators/typescript.md

@@ -42,6 +42,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |sortModelPropertiesByRequiredFlag|Sort model properties to place required parameters before optional parameters.| |true|
 |sortParamsByRequiredFlag|Sort method arguments to place required parameters before optional parameters.| |true|
 |supportsES6|Generate code that conforms to ES6.| |false|
+|typescriptMajorVersion|Specify the major version of TypeScript to use in the client code. Default is 5.| |5|
 |useErasableSyntax|Use erasable syntax for the generated code. This is a temporary feature and will be removed in the future.| |false|
 |useInversify|Enable this to generate decorators and service identifiers for the InversifyJS inversion of control container. If you set 'deno' as 'platform', the generator will process this value as 'disable'.| |false|
 |useObjectParameters|Use aggregate parameter objects as function arguments for api operations instead of passing each parameter as a separate function argument.| |false|

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

@@ -78,6 +78,9 @@ public class TypeScriptClientCodegen extends AbstractTypeScriptClientCodegen imp
     private static final String USE_OBJECT_PARAMS_SWITCH = "useObjectParameters";
     private static final String USE_OBJECT_PARAMS_DESC = "Use aggregate parameter objects as function arguments for api operations instead of passing each parameter as a separate function argument.";
 
+    protected static final String TYPESCRIPT_MAJOR_VERSION_SWTICH = "typescriptMajorVersion";
+    private static final String TYPESCRIPT_MAJOR_VERSION_DESC = "Specify the major version of TypeScript to use in the client code. Default is 5.";
+
     public static final String USE_ERASABLE_SYNTAX = "useErasableSyntax";
     public static final String USE_ERASABLE_SYNTAX_DESC = "Use erasable syntax for the generated code. This is a temporary feature and will be removed in the future.";
 
@@ -97,6 +100,9 @@ public class TypeScriptClientCodegen extends AbstractTypeScriptClientCodegen imp
     protected String snapshot = null;
     protected ENUM_PROPERTY_NAMING_TYPE enumPropertyNaming = ENUM_PROPERTY_NAMING_TYPE.PascalCase;
 
+    @Getter @Setter
+    protected String typescriptMajorVersion = "5";
+
     private final DateTimeFormatter iso8601Date = DateTimeFormatter.ISO_DATE;
     private final DateTimeFormatter iso8601DateTime = DateTimeFormatter.ISO_DATE_TIME;
 
@@ -131,6 +137,7 @@ public TypeScriptClientCodegen() {
         cliOptions.add(new CliOption(TypeScriptClientCodegen.USE_RXJS_SWITCH, TypeScriptClientCodegen.USE_RXJS_SWITCH_DESC).defaultValue("false"));
         cliOptions.add(new CliOption(TypeScriptClientCodegen.USE_OBJECT_PARAMS_SWITCH, TypeScriptClientCodegen.USE_OBJECT_PARAMS_DESC).defaultValue("false"));
         cliOptions.add(new CliOption(TypeScriptClientCodegen.USE_INVERSIFY_SWITCH, TypeScriptClientCodegen.USE_INVERSIFY_SWITCH_DESC).defaultValue("false"));
+        cliOptions.add(new CliOption(TypeScriptClientCodegen.TYPESCRIPT_MAJOR_VERSION_SWTICH, TypeScriptClientCodegen.TYPESCRIPT_MAJOR_VERSION_DESC).defaultValue(this.getTypescriptMajorVersion()));
         cliOptions.add(new CliOption(TypeScriptClientCodegen.IMPORT_FILE_EXTENSION_SWITCH, TypeScriptClientCodegen.IMPORT_FILE_EXTENSION_SWITCH_DESC));
         cliOptions.add(new CliOption(TypeScriptClientCodegen.USE_ERASABLE_SYNTAX, TypeScriptClientCodegen.USE_ERASABLE_SYNTAX_DESC).defaultValue("false"));
 
@@ -495,6 +502,8 @@ public void processOpts() {
         if (additionalProperties.containsKey(NPM_REPOSITORY)) {
             setNpmRepository(additionalProperties.get(NPM_REPOSITORY).toString());
         }
+
+        additionalProperties.put(TYPESCRIPT_MAJOR_VERSION_SWTICH, typescriptMajorVersion);
     }
 
     private String getHttpLibForFramework(String object) {

modules/openapi-generator/src/main/resources/typescript/package.mustache

@@ -71,7 +71,7 @@
     "es6-promise": "^4.2.4"
   },
   "devDependencies": {
-    "typescript": "^4.0"
+    "typescript": "^{{typescriptMajorVersion}}.0"
   }{{#npmRepository}},{{/npmRepository}}
 {{#npmRepository}}
   "publishConfig":{