fix support multiple values for python-platform #3440

crates/pyrefly_config/src/args.rs

@@ -80,7 +80,7 @@ pub struct ConfigOverrideArgs {
 
     /// The platform any `sys.platform` checks should evaluate against.
     #[arg(long)]
-    python_platform: Option<PythonPlatform>,
+    python_platform: Option<Vec<PythonPlatform>>,
 
     /// Directories containing third-party package imports, searched
     /// after first checking `search_path` and `typeshed`.
@@ -305,7 +305,8 @@ impl ConfigOverrideArgs {
             config.synthesized_preset_reason = Some(SynthesizedPresetReason::UserOverride);
         }
         if let Some(x) = &self.python_platform {
-            config.python_environment.python_platform = Some(x.clone());
+            config.python_environment.python_platform =
+                Some(PythonPlatform::new_platforms(x.iter().cloned()));
         }
         if let Some(x) = &self.python_version {
             config.python_environment.python_version = Some(*x);
@@ -482,3 +483,47 @@ impl ConfigOverrideArgs {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn repeated_python_platform_flags_merge() {
+        let args = ConfigOverrideArgs::parse_from([
+            "pyrefly",
+            "--python-platform",
+            "linux",
+            "--python-platform",
+            "win32",
+        ]);
+        args.validate().unwrap();
+        let (config, errors) = args.override_config(ConfigFile::default());
+        assert!(errors.is_empty());
+        assert_eq!(
+            config.python_environment.python_platform,
+            Some(PythonPlatform::new_many(vec![
+                "linux".to_owned(),
+                "win32".to_owned()
+            ]))
+        );
+    }
+
+    #[test]
+    fn repeated_python_platform_flags_all_wins() {
+        let args = ConfigOverrideArgs::parse_from([
+            "pyrefly",
+            "--python-platform",
+            "all",
+            "--python-platform",
+            "linux",
+        ]);
+        args.validate().unwrap();
+        let (config, errors) = args.override_config(ConfigFile::default());
+        assert!(errors.is_empty());
+        assert_eq!(
+            config.python_environment.python_platform,
+            Some(PythonPlatform::All)
+        );
+    }
+}

crates/pyrefly_config/src/config.rs

@@ -1764,6 +1764,67 @@ mod tests {
         );
     }
 
+    #[test]
+    fn deserialize_python_platform_list() {
+        let config = ConfigFile::parse_config(
+            r#"
+            python-platform = ["linux", "win32"]
+            "#,
+        )
+        .unwrap();
+        assert_eq!(
+            config.python_environment.python_platform,
+            Some(PythonPlatform::new_many(vec![
+                "linux".to_owned(),
+                "win32".to_owned()
+            ]))
+        );
+
+        let config = ConfigFile::parse_config(
+            r#"
+            python-platform = "linux"
+            "#,
+        )
+        .unwrap();
+        assert_eq!(
+            config.python_environment.python_platform,
+            Some(PythonPlatform::linux())
+        );
+
+        let config = ConfigFile::parse_config(
+            r#"
+            python-platform = "all"
+            "#,
+        )
+        .unwrap();
+        assert_eq!(
+            config.python_environment.python_platform,
+            Some(PythonPlatform::All)
+        );
+
+        let config = ConfigFile::parse_config(
+            r#"
+            python-platform = ["all", "linux"]
+            "#,
+        )
+        .unwrap();
+        assert_eq!(
+            config.python_environment.python_platform,
+            Some(PythonPlatform::All)
+        );
+
+        let config = ConfigFile::parse_config(
+            r#"
+            python-platform = []
+            "#,
+        )
+        .unwrap();
+        assert_eq!(
+            config.python_environment.python_platform,
+            Some(PythonPlatform::new_many(Vec::new()))
+        );
+    }
+
     #[test]
     fn deserialize_pyrefly_config_snake_case() {
         let config_str = r#"