From 259bf47798aac53d7ab4378bde6def5afd53a7e1 Mon Sep 17 00:00:00 2001
From: Aivaras Saulius <aivaras.saulius@nordsec.com>
Date: Tue, 23 Jul 2024 14:28:55 +0300
Subject: [PATCH] Add option to convert null strings to empty

---
 CHANGELOG.md                      | 4 ++++
 bindgen/src/gen_cs/mod.rs         | 1 +
 bindgen/templates/StringHelper.cs | 7 +++++++
 docs/CONFIGURATION.md             | 2 ++
 4 files changed, 14 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d5bf69e..aa5e098 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+### v0.8.1+v0.25.0
+
+- Add a configuration option `null_string_to_empty` to convert non-optional null strings to empty strings
+
 ----
 
 ### v0.8.0+v0.25.0
diff --git a/bindgen/src/gen_cs/mod.rs b/bindgen/src/gen_cs/mod.rs
index e9233b4..bf64157 100644
--- a/bindgen/src/gen_cs/mod.rs
+++ b/bindgen/src/gen_cs/mod.rs
@@ -38,6 +38,7 @@ pub struct Config {
     external_packages: HashMap<String, String>,
     global_methods_class_name: Option<String>,
     access_modifier: Option<String>,
+    null_string_to_empty: Option<bool>,
 }
 
 #[derive(Debug, Default, Clone, Serialize, Deserialize)]
diff --git a/bindgen/templates/StringHelper.cs b/bindgen/templates/StringHelper.cs
index 69a928d..3df652b 100644
--- a/bindgen/templates/StringHelper.cs
+++ b/bindgen/templates/StringHelper.cs
@@ -24,6 +24,13 @@ public override string Read(BigEndianStream stream) {
     }
 
     public override RustBuffer Lower(string value) {
+        {%- match config.null_string_to_empty %}
+        {%- when Some(true) %}
+        if (value == null) {
+            value = "";
+        }
+        {%- when _ %}
+        {%- endmatch %}
         var bytes = System.Text.Encoding.UTF8.GetBytes(value);
         var rbuf = RustBuffer.Alloc(bytes.Length);
         rbuf.AsWriteableStream().WriteBytes(bytes);
diff --git a/docs/CONFIGURATION.md b/docs/CONFIGURATION.md
index 62ac6b6..ff8e38e 100644
--- a/docs/CONFIGURATION.md
+++ b/docs/CONFIGURATION.md
@@ -55,3 +55,5 @@ uniffi-bindgen-cs path/to/definitions.udl --config path/to/uniffi.toml
     ```
 
 - `access_modifier` - override the default `internal` access modifier for "exported" uniffi symbols.
+
+- `null_string_to_empty` - when set to `true`, `null` strings will be converted to empty strings even if they are not optional.