From 2e740e5cf26c24039a8b78e66cc7ecd94e65b82d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uli=20K=C3=B6hler?= <ukoehler@techoverflow.net>
Date: Sat, 1 Nov 2025 05:23:23 +0100
Subject: [PATCH] Implement parsing of the <Comment> tag

---
 src/parser/conversions.rs | 13 +++++++++
 src/parser/mod.rs         |  1 +
 src/structs.rs            |  1 +
 tests/comment.rs          | 56 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 71 insertions(+)
 create mode 100644 tests/comment.rs

diff --git a/src/parser/conversions.rs b/src/parser/conversions.rs
index f5a7d9f..82b1d4a 100644
--- a/src/parser/conversions.rs
+++ b/src/parser/conversions.rs
@@ -272,10 +272,23 @@ impl TryFrom<Device> for S::Device {
             .map(S::Pdo::try_from)
             .collect::<Result<_>>()?;
 
+        let comment = d
+            .items
+            .iter()
+            .filter_map(|p| {
+                if let DeviceProperty::Comment(c) = p {
+                    Some(c.clone())
+                } else {
+                    None
+                }
+            })
+            .next();
+
         Ok(S::Device {
             physics: d.Physics,
             name,
             desc,
+            comment,
             product_code,
             revision_no,
             sm,
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 79bf794..92b8489 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -100,6 +100,7 @@ pub struct Name {
 pub enum DeviceProperty {
     Type(DeviceType),
     Name(Vec<Name>),
+    Comment(String),
     RxPdo(Vec<RxPdo>),
     TxPdo(Vec<TxPdo>),
     Sm(Vec<Sm>),
diff --git a/src/structs.rs b/src/structs.rs
index b3edcc3..7ed81e0 100644
--- a/src/structs.rs
+++ b/src/structs.rs
@@ -57,6 +57,7 @@ pub struct Device {
     pub physics: Option<String>,
     pub name: Names,
     pub desc: String,
+    pub comment: Option<String>,
     pub product_code: Option<u32>,
     pub revision_no: Option<u32>,
     pub sm: Vec<Sm>,
diff --git a/tests/comment.rs b/tests/comment.rs
new file mode 100644
index 0000000..918a71f
--- /dev/null
+++ b/tests/comment.rs
@@ -0,0 +1,56 @@
+use ethercat_esi::EtherCatInfo;
+
+#[test]
+fn parses_optional_device_comment() {
+    // Minimal ESI with a Device Comment
+    let xml = r##"
+        <EtherCATInfo Version="1.0">
+          <Vendor>
+            <Id>#x00000002</Id>
+            <Name>Demo Vendor</Name>
+          </Vendor>
+          <Descriptions>
+            <Groups/>
+            <Devices>
+              <Device>
+                <Type ProductCode="#x1" RevisionNo="#x1">Demo Device</Type>
+                <Name>Device Name</Name>
+                <Comment>This is a demo device.</Comment>
+              </Device>
+            </Devices>
+          </Descriptions>
+        </EtherCATInfo>
+    "##;
+
+    let esi = EtherCatInfo::from_xml_str(xml).expect("parse ESI");
+    assert_eq!(esi.description.devices.len(), 1);
+    let dev = &esi.description.devices[0];
+    assert_eq!(dev.desc, "Demo Device");
+    assert_eq!(dev.comment.as_deref(), Some("This is a demo device."));
+}
+
+#[test]
+fn device_comment_is_optional() {
+    // Same as above but without Comment tag
+    let xml = r##"
+        <EtherCATInfo Version="1.0">
+          <Vendor>
+            <Id>#x00000002</Id>
+            <Name>Demo Vendor</Name>
+          </Vendor>
+          <Descriptions>
+            <Groups/>
+            <Devices>
+              <Device>
+                <Type ProductCode="#x1" RevisionNo="#x1">Demo Device</Type>
+                <Name>Device Name</Name>
+              </Device>
+            </Devices>
+          </Descriptions>
+        </EtherCATInfo>
+    "##;
+
+    let esi = EtherCatInfo::from_xml_str(xml).expect("parse ESI");
+    let dev = &esi.description.devices[0];
+    assert!(dev.comment.is_none());
+}