From 9f9afbc77254bc1e34d859c5c650eab571e7b5ce Mon Sep 17 00:00:00 2001
From: Tomasz Durda <tomekdur@wp.pl>
Date: Mon, 26 May 2025 10:25:59 +0200
Subject: [PATCH 1/2] Added tests for seq=<bool> syntax

---
 tests/regression/issue_x.rs | 81 +++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 tests/regression/issue_x.rs

diff --git a/tests/regression/issue_x.rs b/tests/regression/issue_x.rs
new file mode 100644
index 000000000..2065aeb12
--- /dev/null
+++ b/tests/regression/issue_x.rs
@@ -0,0 +1,81 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "type", seq=false)]
+enum ParentChildNoSeq {
+    Title,
+    #[serde(untagged)]
+    SubStructure(ChildNoSeq),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "type", seq=false)]
+enum ParentNoSeq {
+    Title,
+    #[serde(untagged)]
+    SubStructure(Child),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "type")]
+enum Parent {
+    Title,
+    #[serde(untagged)]
+    SubStructure(Child),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "type", seq=true)]
+enum ParentSeq {
+    Title,
+    #[serde(untagged)]
+    SubStructure(Child),
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "subtype", seq=false)]
+enum ChildNoSeq {
+    Topic, Sidebar
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+#[serde(tag = "subtype")]
+enum Child {
+    Topic, Sidebar
+}
+
+#[test]
+fn test() {
+    // Using seq=false on every level will cause it to fail
+    let v  = serde_json::from_str::<ParentChildNoSeq>("[0]");
+    assert!(v.is_err());
+
+    // Using seq=false will cause it to fail, but if the child is not seq=true, the  child will succeed
+    let v  = serde_json::from_str::<ParentNoSeq>("[0]");
+    assert!(matches!(v, Ok(ParentNoSeq::SubStructure(Child::Topic))));
+
+    // Using default beahvior will succeed
+    let v  = serde_json::from_str::<Parent>("[0]");
+    assert!(v.is_ok());
+
+    // Using seq=true beahvior will succeed
+    let v  = serde_json::from_str::<ParentSeq>("[0]");
+    assert!(v.is_ok());
+
+    // As in the docs:
+    // There is no explicit tag identifying which variant the data contains. Serde will try to
+    // match the data against each variant in order and the first one that deserializes
+    // successfully is the one returned.
+    let v = serde_json::from_str::<Parent>("[\"Topic\"]");
+    assert!(v.is_ok());
+    let v = serde_json::from_str::<Child>("[\"Topic\"]");
+    assert!(v.is_ok());
+
+    // With seq=false it should fail
+    let v = serde_json::from_str::<ChildNoSeq>("[\"Topic\"]");
+    assert!(v.is_err());
+    let v = serde_json::from_str::<ParentNoSeq>("[\"Topic\"]");
+    assert!(v.is_ok());
+    let v = serde_json::from_str::<ParentChildNoSeq>("[\"Topic\"]");
+    assert!(v.is_err());
+}

From a9f09d484691e7ab5f857b93dc40090b777122f7 Mon Sep 17 00:00:00 2001
From: Tomasz Durda <tomekdur@wp.pl>
Date: Tue, 27 May 2025 08:27:23 +0200
Subject: [PATCH 2/2] Updated tests to match new naming

---
 tests/regression/{issue_x.rs => issue_1263.rs} | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
 rename tests/regression/{issue_x.rs => issue_1263.rs} (93%)

diff --git a/tests/regression/issue_x.rs b/tests/regression/issue_1263.rs
similarity index 93%
rename from tests/regression/issue_x.rs
rename to tests/regression/issue_1263.rs
index 2065aeb12..b0704aaad 100644
--- a/tests/regression/issue_x.rs
+++ b/tests/regression/issue_1263.rs
@@ -1,7 +1,7 @@
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Serialize, Deserialize)]
-#[serde(tag = "type", seq=false)]
+#[serde(tag = "type", seq_form=false)]
 enum ParentChildNoSeq {
     Title,
     #[serde(untagged)]
@@ -9,7 +9,7 @@ enum ParentChildNoSeq {
 }
 
 #[derive(Debug, Serialize, Deserialize)]
-#[serde(tag = "type", seq=false)]
+#[serde(tag = "type", seq_form=false)]
 enum ParentNoSeq {
     Title,
     #[serde(untagged)]
@@ -25,7 +25,7 @@ enum Parent {
 }
 
 #[derive(Debug, Serialize, Deserialize)]
-#[serde(tag = "type", seq=true)]
+#[serde(tag = "type", seq_form=true)]
 enum ParentSeq {
     Title,
     #[serde(untagged)]
@@ -33,7 +33,7 @@ enum ParentSeq {
 }
 
 #[derive(Debug, Serialize, Deserialize)]
-#[serde(tag = "subtype", seq=false)]
+#[serde(tag = "subtype", seq_form=false)]
 enum ChildNoSeq {
     Topic, Sidebar
 }