fix(rlang): module not working on MacOs (starship#2880)

Fix rlang module and refactor other modules to use new method.

src/modules/java.rs

@@ -1,5 +1,6 @@
 use crate::configs::java::JavaConfig;
 use crate::formatter::{StringFormatter, VersionFormatter};
+use crate::utils::get_command_string_output;
 use std::path::PathBuf;
 
 use super::{Context, Module, RootModuleConfig};
@@ -64,12 +65,8 @@ fn get_java_version(context: &Context, config: &JavaConfig) -> Option<String> {
         })
         .unwrap_or_else(|| String::from("java"));
 
-    let output = context.exec_cmd(&java_command, &["-Xinternalversion"])?;
-    let java_version = if output.stdout.is_empty() {
-        output.stderr
-    } else {
-        output.stdout
-    };
+    let command = context.exec_cmd(&java_command, &["-Xinternalversion"])?;
+    let java_version = get_command_string_output(command);
 
     format_java_version(&java_version, config.version_format)
 }

src/modules/kotlin.rs

@@ -3,6 +3,7 @@ use super::{Context, Module, RootModuleConfig};
 use crate::configs::kotlin::KotlinConfig;
 use crate::formatter::StringFormatter;
 use crate::formatter::VersionFormatter;
+use crate::utils::get_command_string_output;
 
 use regex::Regex;
 const KOTLIN_VERSION_PATTERN: &str = "(?P<version>[\\d\\.]+[\\d\\.]+[\\d\\.]+)";
@@ -60,17 +61,10 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 }
 
 fn get_kotlin_version(context: &Context, kotlin_binary: &str) -> Option<String> {
-    match context.exec_cmd(kotlin_binary, &["-version"]) {
-        Some(output) => {
-            let kotlin_output = if output.stdout.is_empty() {
-                output.stderr
-            } else {
-                output.stdout
-            };
-            parse_kotlin_version(&kotlin_output)
-        }
-        None => None,
-    }
+    let command = context.exec_cmd(kotlin_binary, &["-version"])?;
+    let kotlin_version = get_command_string_output(command);
+
+    parse_kotlin_version(&kotlin_version)
 }
 
 fn parse_kotlin_version(kotlin_stdout: &str) -> Option<String> {

src/modules/lua.rs

@@ -3,6 +3,7 @@ use super::{Context, Module, RootModuleConfig};
 use crate::configs::lua::LuaConfig;
 use crate::formatter::StringFormatter;
 use crate::formatter::VersionFormatter;
+use crate::utils::get_command_string_output;
 
 /// Creates a module with the current Lua version
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
@@ -57,12 +58,8 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 }
 
 fn get_lua_version(context: &Context, lua_binary: &str) -> Option<String> {
-    let output = context.exec_cmd(lua_binary, &["-v"])?;
-    let lua_version = if output.stdout.is_empty() {
-        output.stderr
-    } else {
-        output.stdout
-    };
+    let command = context.exec_cmd(lua_binary, &["-v"])?;
+    let lua_version = get_command_string_output(command);
 
     parse_lua_version(&lua_version)
 }

src/modules/python.rs

@@ -5,6 +5,7 @@ use super::{Context, Module, RootModuleConfig};
 use crate::configs::python::PythonConfig;
 use crate::formatter::StringFormatter;
 use crate::formatter::VersionFormatter;
+use crate::utils::get_command_string_output;
 
 /// Creates a module with the current Python version and, if active, virtual environment.
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
@@ -73,13 +74,7 @@ fn get_python_version(context: &Context, config: &PythonConfig) -> Option<String
         .0
         .iter()
         .find_map(|binary| context.exec_cmd(binary, &["--version"]))
-        .map(|output| {
-            if output.stdout.is_empty() {
-                output.stderr
-            } else {
-                output.stdout
-            }
-        })?;
+        .map(get_command_string_output)?;
 
     format_python_version(&version, config.version_format)
 }

src/modules/rlang.rs

@@ -3,6 +3,7 @@ use crate::formatter::VersionFormatter;
 
 use crate::configs::rlang::RLangConfig;
 use crate::formatter::StringFormatter;
+use crate::utils::get_command_string_output;
 
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("rlang");
@@ -55,7 +56,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 }
 
 fn get_r_version(context: &Context) -> Option<String> {
-    let r_version = context.exec_cmd("R", &["--version"])?.stderr;
+    let r_version = get_command_string_output(context.exec_cmd("R", &["--version"])?);
     parse_version(&r_version)
 }
 

src/modules/scala.rs

@@ -3,6 +3,7 @@ use crate::formatter::StringFormatter;
 
 use super::{Context, Module, RootModuleConfig};
 use crate::formatter::VersionFormatter;
+use crate::utils::get_command_string_output;
 
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("scala");
@@ -56,13 +57,8 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 }
 
 fn get_scala_version(context: &Context) -> Option<String> {
-    let output = context.exec_cmd("scalac", &["-version"])?;
-    let scala_version = if output.stdout.is_empty() {
-        output.stderr
-    } else {
-        output.stdout
-    };
-
+    let command = context.exec_cmd("scalac", &["-version"])?;
+    let scala_version = get_command_string_output(command);
     parse_scala_version(&scala_version)
 }
 

src/utils.rs

@@ -18,12 +18,21 @@ pub fn read_file<P: AsRef<Path> + Debug>(file_name: P) -> Result<String> {
     if result.is_err() {
         log::debug!("Error reading file: {:?}", result);
     } else {
-        log::trace!("File read sucessfully");
+        log::trace!("File read successfully");
     };
 
     result
 }
 
+/// Reads command output from stderr or stdout depending on to which stream program streamed it's output
+pub fn get_command_string_output(command: CommandOutput) -> String {
+    if command.stdout.is_empty() {
+        command.stderr
+    } else {
+        command.stdout
+    }
+}
+
 /// Attempt to resolve `binary_name` from and creates a new `Command` pointing at it
 /// This allows executing cmd files on Windows and prevents running executable from cwd on Windows
 /// This function also initialises std{err,out,in} to protect against processes changing the console mode
@@ -631,4 +640,17 @@ mod tests {
             test
         );
     }
+    #[test]
+    fn test_get_command_string_output() {
+        let case1 = CommandOutput {
+            stdout: String::from("stdout"),
+            stderr: String::from("stderr"),
+        };
+        assert_eq!(get_command_string_output(case1), "stdout");
+        let case2 = CommandOutput {
+            stdout: String::from(""),
+            stderr: String::from("stderr"),
+        };
+        assert_eq!(get_command_string_output(case2), "stderr");
+    }
 }