Modernize option defaults for the next major release

packages/quicktype-core/src/language/CPlusPlus/CPlusPlusRenderer.ts

@@ -2144,8 +2144,14 @@ export class CPlusPlusRenderer extends ConvenienceRenderer {
                             ],
                             false,
                             () => {
+                                // A JSON null must become an *empty*
+                                // optional.  Only `optType<T>()` guarantees
+                                // that: the factory would wrap a
+                                // default-constructed T (std::make_optional
+                                // and std::make_shared both do), turning
+                                // null into 0/""/{} on round-trip.
                                 this.emitLine(
-                                    `if (j.is_null()) return ${factory}<T>(); else return ${factory}<T>(j.get<T>());`,
+                                    `if (j.is_null()) return ${optType}<T>(); else return ${factory}<T>(j.get<T>());`,
                                 );
                             },
                         );

packages/quicktype-core/src/language/CPlusPlus/language.ts

@@ -104,7 +104,7 @@ export const cPlusPlusOptions = {
     boost: new BooleanOption(
         "boost",
         "Require a dependency on boost. Without boost, C++17 is required",
-        true,
+        false,
     ),
     hideNullOptional: new BooleanOption(
         "hide-null-optional",

packages/quicktype-core/src/language/CSharp/CSharpRenderer.ts

@@ -15,11 +15,11 @@ import { type Sourcelike, maybeAnnotated } from "../../Source.js";
 import { assert } from "../../support/Support.js";
 import type { TargetLanguage } from "../../TargetLanguage.js";
 import { followTargetType } from "../../Transformers.js";
-import type {
-    ClassProperty,
-    ClassType,
-    EnumType,
-    Type,
+import {
+    type ClassProperty,
+    type ClassType,
+    type EnumType,
+    type Type,
     UnionType,
 } from "../../Type/index.js";
 import {
@@ -187,6 +187,18 @@ export class CSharpRenderer extends ConvenienceRenderer {
         withIssues = false,
     ): Sourcelike {
         t = followTargetType(t);
+        // A nullable union already renders with its own "?" through
+        // csType's union case; unwrap it so the annotation is applied
+        // exactly once.  Without this, an optional property whose type
+        // is e.g. `string | null` would render as `string??` at C# 8
+        // (and a nullable value-type union as `long??` at any version).
+        if (t instanceof UnionType) {
+            const nullable = nullableFromUnion(t);
+            if (nullable !== null) {
+                t = followTargetType(nullable);
+            }
+        }
+
         const csType = this.csType(t, follow, withIssues);
         if (isValueType(t) || this._csOptions.version >= 8) {
             return [csType, "?"];

packages/quicktype-core/src/language/CSharp/NewtonSoftCSharpRenderer.ts

@@ -197,7 +197,10 @@ export class NewtonsoftCSharpRenderer extends CSharpRenderer {
 
         this.emitLine("#pragma warning restore CS8618");
         this.emitLine("#pragma warning restore CS8601");
+        this.emitLine("#pragma warning restore CS8602");
         this.emitLine("#pragma warning restore CS8603");
+        this.emitLine("#pragma warning restore CS8604");
+        this.emitLine("#pragma warning restore CS8625");
         this.emitLine("#pragma warning restore CS8765");
     }
 
@@ -239,7 +242,13 @@ export class NewtonsoftCSharpRenderer extends CSharpRenderer {
             this.emitLine("#nullable enable");
             this.emitLine("#pragma warning disable CS8618");
             this.emitLine("#pragma warning disable CS8601");
+            // CS8602/CS8604/CS8625: the emitted constraint-check and
+            // string-transformer helpers dereference and pass around
+            // Deserialize<T>() results, which are nullable under NRT.
+            this.emitLine("#pragma warning disable CS8602");
             this.emitLine("#pragma warning disable CS8603");
+            this.emitLine("#pragma warning disable CS8604");
+            this.emitLine("#pragma warning disable CS8625");
             this.emitLine("#pragma warning disable CS8765");
         }
     }

packages/quicktype-core/src/language/CSharp/SystemTextJsonCSharpRenderer.ts

@@ -196,6 +196,7 @@ export class SystemTextJsonCSharpRenderer extends CSharpRenderer {
 
         this.emitLine("#pragma warning restore CS8618");
         this.emitLine("#pragma warning restore CS8601");
+        this.emitLine("#pragma warning restore CS8602");
         this.emitLine("#pragma warning restore CS8603");
     }
 
@@ -237,6 +238,9 @@ export class SystemTextJsonCSharpRenderer extends CSharpRenderer {
         this.emitLine("#nullable enable");
         this.emitLine("#pragma warning disable CS8618");
         this.emitLine("#pragma warning disable CS8601");
+        // CS8602: the emitted constraint-check converters dereference
+        // Deserialize<T>() results, which are nullable under NRT.
+        this.emitLine("#pragma warning disable CS8602");
         this.emitLine("#pragma warning disable CS8603");
     }
 

packages/quicktype-core/src/language/CSharp/language.ts

@@ -35,7 +35,7 @@ export const cSharpOptions = {
             NewtonSoft: "NewtonSoft",
             SystemTextJson: "SystemTextJson",
         } as const,
-        "NewtonSoft",
+        "SystemTextJson",
     ),
     useList: new EnumOption(
         "array-type",
@@ -71,7 +71,7 @@ export const cSharpOptions = {
             "6": 6,
             "8": 8,
         } as const,
-        "6",
+        "8",
         "secondary",
     ),
     virtual: new BooleanOption("virtual", "Generate virtual properties", false),

packages/quicktype-core/src/language/Dart/DartRenderer.ts

@@ -266,9 +266,7 @@ export class DartRenderer extends ConvenienceRenderer {
     ): Sourcelike {
         const nullable =
             forceNullable ||
-            (this._options.nullSafety &&
-                t.isNullable &&
-                !this._options.requiredProperties);
+            (t.isNullable && !this._options.requiredProperties);
         const withNullable = (s: Sourcelike): Sourcelike =>
             nullable ? [s, "?"] : s;
         return matchType<Sourcelike>(
@@ -321,11 +319,7 @@ export class DartRenderer extends ConvenienceRenderer {
         list: Sourcelike,
         mapper: Sourcelike,
     ): Sourcelike {
-        if (
-            this._options.nullSafety &&
-            isNullable &&
-            !this._options.requiredProperties
-        ) {
+        if (isNullable && !this._options.requiredProperties) {
             return [
                 list,
                 " == null ? [] : ",
@@ -356,11 +350,7 @@ export class DartRenderer extends ConvenienceRenderer {
         map: Sourcelike,
         valueMapper: Sourcelike,
     ): Sourcelike {
-        if (
-            this._options.nullSafety &&
-            isNullable &&
-            !this._options.requiredProperties
-        ) {
+        if (isNullable && !this._options.requiredProperties) {
             return [
                 "Map.from(",
                 map,
@@ -388,11 +378,7 @@ export class DartRenderer extends ConvenienceRenderer {
         classType: ClassType,
         dynamic: Sourcelike,
     ): Sourcelike {
-        if (
-            this._options.nullSafety &&
-            isNullable &&
-            !this._options.requiredProperties
-        ) {
+        if (isNullable && !this._options.requiredProperties) {
             return [
                 dynamic,
                 " == null ? null : ",
@@ -431,10 +417,7 @@ export class DartRenderer extends ConvenienceRenderer {
             (_nullType) => dynamic, // FIXME: check null
             (_boolType) => dynamic,
             (_integerType) => dynamic,
-            (_doubleType) => [
-                dynamic,
-                this._options.nullSafety ? "?.toDouble()" : ".toDouble()",
-            ],
+            (_doubleType) => [dynamic, "?.toDouble()"],
             (_stringType) => dynamic,
             (arrayType) =>
                 this.mapList(
@@ -469,8 +452,7 @@ export class DartRenderer extends ConvenienceRenderer {
                     defined(this._enumValues.get(enumType)),
                     ".map[",
                     dynamic,
-                    this._options.nullSafety &&
-                    (!isNullable || this._options.requiredProperties)
+                    !isNullable || this._options.requiredProperties
                         ? "]!"
                         : "]",
                 ];
@@ -493,8 +475,7 @@ export class DartRenderer extends ConvenienceRenderer {
                     case "date":
                         if (
                             (transformedStringType.isNullable || isNullable) &&
-                            !this._options.requiredProperties &&
-                            this._options.nullSafety
+                            !this._options.requiredProperties
                         ) {
                             return [
                                 dynamic,
@@ -544,7 +525,6 @@ export class DartRenderer extends ConvenienceRenderer {
                 ),
             (_classType) => {
                 if (
-                    this._options.nullSafety &&
                     (_classType.isNullable || isNullable) &&
                     !this._options.requiredProperties
                 ) {
@@ -588,7 +568,6 @@ export class DartRenderer extends ConvenienceRenderer {
                 switch (transformedStringType.kind) {
                     case "date-time":
                         if (
-                            this._options.nullSafety &&
                             !this._options.requiredProperties &&
                             (transformedStringType.isNullable || isNullable)
                         ) {
@@ -598,7 +577,6 @@ export class DartRenderer extends ConvenienceRenderer {
                         return [dynamic, ".toIso8601String()"];
                     case "date":
                         if (
-                            this._options.nullSafety &&
                             !this._options.requiredProperties &&
                             (transformedStringType.isNullable || isNullable)
                         ) {
@@ -642,8 +620,8 @@ export class DartRenderer extends ConvenienceRenderer {
             this.forEachClassProperty(c, "none", (name, _, prop) => {
                 const required =
                     this._options.requiredProperties ||
-                    (this._options.nullSafety &&
-                        (!prop.type.isNullable || !prop.isOptional));
+                    !prop.type.isNullable ||
+                    !prop.isOptional;
                 this.emitLine(required ? "required " : "", "this.", name, ",");
             });
         });
@@ -869,9 +847,8 @@ export class DartRenderer extends ConvenienceRenderer {
 
                                 const required =
                                     this._options.requiredProperties ||
-                                    (this._options.nullSafety &&
-                                        (!prop.type.isNullable ||
-                                            !prop.isOptional));
+                                    !prop.type.isNullable ||
+                                    !prop.isOptional;
                                 if (this._options.useJsonAnnotation) {
                                     this.classPropertyCounter++;
                                     this.emitLine(

packages/quicktype-core/src/language/Dart/language.ts

@@ -15,7 +15,6 @@ import type { LanguageName, RendererOptions } from "../../types.js";
 import { DartRenderer } from "./DartRenderer.js";
 
 export const dartOptions = {
-    nullSafety: new BooleanOption("null-safety", "Null Safety", true),
     justTypes: new BooleanOption("just-types", "Types only", false),
     codersInClass: new BooleanOption(
         "coders-in-class",
@@ -36,7 +35,7 @@ export const dartOptions = {
     finalProperties: new BooleanOption(
         "final-props",
         "Make all properties final",
-        false,
+        true,
     ),
     generateCopyWith: new BooleanOption(
         "copy-with",

packages/quicktype-core/src/language/Haskell/language.ts

@@ -19,7 +19,7 @@ export const haskellOptions = {
             array: false,
             list: true,
         } as const,
-        "array",
+        "list",
     ),
     moduleName: new StringOption(
         "module",

packages/quicktype-core/src/language/Java/JavaJacksonRenderer.ts

@@ -206,11 +206,16 @@ export class JacksonRenderer extends JavaRenderer {
             const { fieldName } = this.unionField(u, t);
             const rendered = this.javaTypeWithoutGenerics(true, t);
             if (this._options.useList && t instanceof ArrayType) {
+                // The TypeReference must carry the full generic type:
+                // a raw `TypeReference<List>` would make Jackson accept
+                // any element type, so schema-invalid inputs (which the
+                // expected-failure fixtures rely on rejecting) would
+                // deserialize successfully.
                 this.emitLine(
                     "value.",
                     fieldName,
                     " = jsonParser.readValueAs(new TypeReference<",
-                    rendered,
+                    this.javaType(true, t),
                     ">() {});",
                 );
             } else if (

packages/quicktype-core/src/language/Java/language.ts

@@ -22,7 +22,7 @@ export const javaOptions = {
         "array-type",
         "Use T[] or List<T>",
         { array: false, list: true } as const,
-        "array",
+        "list",
     ),
     justTypes: new BooleanOption("just-types", "Plain types only", false),
     dateTimeProvider: new EnumOption(

packages/quicktype-core/src/language/Kotlin/language.ts

@@ -33,7 +33,7 @@ export const kotlinOptions = {
             klaxon: "Klaxon",
             kotlinx: "KotlinX",
         } as const,
-        "klaxon",
+        "jackson",
     ),
     acronymStyle: acronymOption(AcronymStyleOptions.Pascal),
     packageName: new StringOption("package", "Package", "PACKAGE", "quicktype"),

packages/quicktype-core/src/language/Rust/RustRenderer.ts

@@ -376,11 +376,7 @@ export class RustRenderer extends ConvenienceRenderer {
         }
 
         this.ensureBlankLine();
-        if (this._options.edition2018) {
-            this.emitLine("use serde::{Serialize, Deserialize};");
-        } else {
-            this.emitLine("extern crate serde_derive;");
-        }
+        this.emitLine("use serde::{Serialize, Deserialize};");
 
         if (this.haveMaps) {
             this.emitLine("use std::collections::HashMap;");

packages/quicktype-core/src/language/Rust/language.ts

@@ -28,10 +28,10 @@ export const rustOptions = {
             crate: Visibility.Crate,
             public: Visibility.Public,
         } as const,
-        "private",
+        "public",
     ),
-    deriveDebug: new BooleanOption("derive-debug", "Derive Debug impl", false),
-    deriveClone: new BooleanOption("derive-clone", "Derive Clone impl", false),
+    deriveDebug: new BooleanOption("derive-debug", "Derive Debug impl", true),
+    deriveClone: new BooleanOption("derive-clone", "Derive Clone impl", true),
     derivePartialEq: new BooleanOption(
         "derive-partial-eq",
         "Derive PartialEq impl",
@@ -42,7 +42,6 @@ export const rustOptions = {
         "Skip serializing empty Option fields",
         false,
     ),
-    edition2018: new BooleanOption("edition-2018", "Edition 2018", true),
     leadingComments: new BooleanOption(
         "leading-comments",
         "Leading Comments",

packages/quicktype-core/src/language/Swift/language.ts

@@ -72,7 +72,7 @@ export const swiftOptions = {
             dense: true,
             normal: false,
         } as const,
-        "dense",
+        "normal",
         "secondary",
     ),
     linux: new BooleanOption(
@@ -91,11 +91,6 @@ export const swiftOptions = {
         "If no matching case is found enum value is set to null",
         false,
     ),
-    swift5Support: new BooleanOption(
-        "swift-5-support",
-        "Renders output in a Swift 5 compatible mode",
-        false,
-    ),
     sendable: new BooleanOption(
         "sendable",
         "Mark generated models as Sendable",

packages/quicktype-core/src/language/TypeScriptFlow/language.ts

@@ -32,7 +32,7 @@ export const tsFlowOptions = {
     preferUnions: new BooleanOption(
         "prefer-unions",
         "Use union type instead of enum",
-        false,
+        true,
     ),
     preferTypes: new BooleanOption(
         "prefer-types",