fix(json): encode empty stdClass fields as {} not []

Empty PhpMixed::Array now serializes as [], so the several places that build a
PHP `new \stdClass` via an empty Array were emitting [] where Composer writes
{}. Use PhpMixed::Object for those empty-object cases:

- InitCommand: require / require-dev
- Locker::fixupJsonDataType: stability-flags / platform / platform-dev
- JsonConfigSource fallback: require/config keys that must stay objects

Align the affected test expectations with Composer: JsonFile::read() decodes
with assoc=true, collapsing the on-disk {} back to [], so reads expect [].

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

5 files changed, 29 insertions, 30 deletions

diff --git a/crates/shirabe/src/command/init_command.rs b/crates/shirabe/src/command/init_command.rs
index ab0e52c..88a2934 100644
--- a/crates/shirabe/src/command/init_command.rs
+++ b/crates/shirabe/src/command/init_command.rs
@@ -226,8 +226,8 @@ impl Command for InitCommand {
                 .unwrap_or_default();
             let formatted = self.format_requirements(req_list)?;
             if formatted.is_empty() {
-                // PHP: new \stdClass — represented as an empty IndexMap (JSON object)
-                PhpMixed::Array(IndexMap::new())
+                // PHP: new \stdClass — empty JSON object
+                PhpMixed::Object(IndexMap::new())
             } else {
                 PhpMixed::Array(
                     formatted
@@ -238,7 +238,7 @@ impl Command for InitCommand {
             }
         } else {
             // PHP: new \stdClass
-            PhpMixed::Array(IndexMap::new())
+            PhpMixed::Object(IndexMap::new())
         };
         options.insert("require".to_string(), require_value);
 
@@ -254,7 +254,7 @@ impl Command for InitCommand {
                 .unwrap_or_default();
             let formatted = self.format_requirements(req_list)?;
             let value = if formatted.is_empty() {
-                PhpMixed::Array(IndexMap::new())
+                PhpMixed::Object(IndexMap::new())
             } else {
                 PhpMixed::Array(
                     formatted
diff --git a/crates/shirabe/src/config/json_config_source.rs b/crates/shirabe/src/config/json_config_source.rs
index 2509239..1ce51ad 100644
--- a/crates/shirabe/src/config/json_config_source.rs
+++ b/crates/shirabe/src/config/json_config_source.rs
@@ -98,7 +98,7 @@ impl JsonConfigSource {
                     && inner.is_empty()
                 {
                     // PHP: $config[$prop] = new \stdClass;
-                    map.insert(prop.to_string(), PhpMixed::Array(IndexMap::new()));
+                    map.insert(prop.to_string(), PhpMixed::Object(IndexMap::new()));
                 }
             }
             for prop in ["psr-0", "psr-4"] {
@@ -108,14 +108,15 @@ impl JsonConfigSource {
                         && let Some(PhpMixed::Array(inner_map)) = autoload_map.get(prop)
                         && inner_map.is_empty()
                     {
-                        autoload_map.insert(prop.to_string(), PhpMixed::Array(IndexMap::new()));
+                        autoload_map.insert(prop.to_string(), PhpMixed::Object(IndexMap::new()));
                     }
                     if let Some(autoload_dev) = map.get_mut("autoload-dev")
                         && let PhpMixed::Array(autoload_dev_map) = autoload_dev
                         && let Some(PhpMixed::Array(inner_map)) = autoload_dev_map.get(prop)
                         && inner_map.is_empty()
                     {
-                        autoload_dev_map.insert(prop.to_string(), PhpMixed::Array(IndexMap::new()));
+                        autoload_dev_map
+                            .insert(prop.to_string(), PhpMixed::Object(IndexMap::new()));
                     }
                 }
             }
@@ -136,7 +137,7 @@ impl JsonConfigSource {
                     && let Some(PhpMixed::Array(inner_map)) = cfg_map.get(prop)
                     && inner_map.is_empty()
                 {
-                    cfg_map.insert(prop.to_string(), PhpMixed::Array(IndexMap::new()));
+                    cfg_map.insert(prop.to_string(), PhpMixed::Object(IndexMap::new()));
                 }
             }
             self.file.borrow().write(config)?;
diff --git a/crates/shirabe/src/package/locker.rs b/crates/shirabe/src/package/locker.rs
index df5e1de..1f123f1 100644
--- a/crates/shirabe/src/package/locker.rs
+++ b/crates/shirabe/src/package/locker.rs
@@ -705,7 +705,8 @@ impl Locker {
                 })
                 .unwrap_or(false);
             if should_replace {
-                lock_data.insert(key.to_string(), PhpMixed::Array(IndexMap::new()));
+                // PHP: new \stdClass() — empty JSON object
+                lock_data.insert(key.to_string(), PhpMixed::Object(IndexMap::new()));
             }
         }
 
diff --git a/crates/shirabe/tests/command/init_command_test.rs b/crates/shirabe/tests/command/init_command_test.rs
index efb3f49..32226f6 100644
--- a/crates/shirabe/tests/command/init_command_test.rs
+++ b/crates/shirabe/tests/command/init_command_test.rs
@@ -159,9 +159,6 @@ fn test_namespace_from_missing_package_name() {
 }
 
 /// @return iterable<string, array{0: array<string, mixed>, 1: array<string, mixed>}>
-///
-/// Empty `require` is `{}` (PHP's `new \stdClass`), not `[]`, to match what the command writes:
-/// shirabe's `json_decode` keeps the empty object/array distinction that PHP collapses.
 fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
     vec![
         // name argument
@@ -169,7 +166,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
             }),
             vec![opt("--name", "test/pkg")],
         ),
@@ -177,7 +174,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
         (
             serde_json::json!({
                 "name": "test/pkg",
-                "require": {},
+                "require": [],
                 "authors": [{ "name": "Mr. Test", "email": "test@example.org" }],
             }),
             vec![
@@ -189,7 +186,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
         (
             serde_json::json!({
                 "name": "test/pkg",
-                "require": {},
+                "require": [],
                 "authors": [{ "name": "Mr. Test" }],
             }),
             vec![opt("--name", "test/pkg"), opt("--author", "Mr. Test")],
@@ -199,7 +196,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "repositories": [{ "type": "vcs", "url": "http://packages.example.com" }],
             }),
             vec![
@@ -215,7 +212,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "repositories": [
                     { "type": "vcs", "url": "http://vcs.example.com" },
                     { "type": "composer", "url": "http://composer.example.com" },
@@ -243,7 +240,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "minimum-stability": "dev",
             }),
             vec![opt("--name", "test/pkg"), opt("--stability", "dev")],
@@ -277,7 +274,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "require-dev": { "first/pkg": "1.0.0" },
             }),
             vec![
@@ -290,7 +287,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "require-dev": { "first/pkg": "1.0.0", "second/pkg": "^3.4" },
             }),
             vec![
@@ -303,7 +300,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "autoload": { "psr-4": { "Test\\Pkg\\": "testMapping/" } },
             }),
             vec![opt("--name", "test/pkg"), opt("--autoload", "testMapping/")],
@@ -313,7 +310,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "homepage": "https://example.org/",
             }),
             vec![
@@ -326,7 +323,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "description": "My first example package",
             }),
             vec![
@@ -339,7 +336,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "type": "project",
             }),
             vec![opt("--name", "test/pkg"), opt("--type", "project")],
@@ -349,7 +346,7 @@ fn run_data_provider() -> Vec<(serde_json::Value, Vec<(PhpMixed, PhpMixed)>)> {
             serde_json::json!({
                 "name": "test/pkg",
                 "authors": [default_authors()],
-                "require": {},
+                "require": [],
                 "license": "MIT",
             }),
             vec![opt("--name", "test/pkg"), opt("--license", "MIT")],
@@ -510,7 +507,7 @@ fn test_run_guess_name_from_dir_sanitizes_dir() {
     let expected = serde_json::json!({
         "name": "vendor-name/foo-bar_baz.qux",
         "authors": [default_authors()],
-        "require": {},
+        "require": [],
     });
     assert_eq!(
         expected,
@@ -562,7 +559,7 @@ fn test_interactive_run() {
         "license": "AGPL-3.0-only",
         "authors": [{ "name": "Mr. Test", "email": "test@example.org" }],
         "minimum-stability": "stable",
-        "require": {},
+        "require": [],
     });
     assert_eq!(expected, read_composer_json(&dir));
 }
diff --git a/crates/shirabe/tests/command/repository_command_test.rs b/crates/shirabe/tests/command/repository_command_test.rs
index 1d104e7..901b9f3 100644
--- a/crates/shirabe/tests/command/repository_command_test.rs
+++ b/crates/shirabe/tests/command/repository_command_test.rs
@@ -34,7 +34,7 @@ fn test_list_with_no_repositories() {
         app_tester.get_display().trim()
     );
     // composer.json should remain unchanged
-    assert_eq!(serde_json::json!({}), read_composer_json());
+    assert_eq!(serde_json::json!([]), read_composer_json());
 
     drop(tear_down);
 }
@@ -216,7 +216,7 @@ fn test_remove_repository() {
     if let Some(repositories) = json.get("repositories") {
         assert_eq!(&serde_json::json!([]), repositories);
     } else {
-        assert_eq!(serde_json::json!({}), json);
+        assert_eq!(serde_json::json!([]), json);
     }
 
     drop(tear_down);
@@ -392,7 +392,7 @@ fn test_disable_and_enable_packagist() {
         )
         .unwrap();
     assert_eq!(0, status_code);
-    assert_eq!(serde_json::json!({}), read_composer_json());
+    assert_eq!(serde_json::json!([]), read_composer_json());
 
     drop(tear_down);
 }