refactor: propagate version formatting errors (#2566)

* refactor: propagate version formatting errors

* refactor: trim version formatting boilerplate

* refactor(node): unwrap version formatting

* docs: fix typo

* docs: remove dots after `version_format`

* feat: lazy version parsing

* refactor(version-formatter): collect segments into string

1 files changed, 35 insertions, 34 deletions

diff --git a/src/modules/rust.rs b/src/modules/rust.rs
index 963522a9c..a465d9798 100644
--- a/src/modules/rust.rs
+++ b/src/modules/rust.rs
@@ -72,27 +72,25 @@ fn get_module_version(context: &Context, config: &RustConfig) -> Option<String>
     // - `rustup show`
     // - `rustup show active-toolchain`
     // - `rustup which`
-    let module_version = if let Some(toolchain) = env_rustup_toolchain(context)
+    if let Some(toolchain) = env_rustup_toolchain(context)
         .or_else(|| execute_rustup_override_list(&context.current_dir))
         .or_else(|| find_rust_toolchain_file(&context))
     {
         match execute_rustup_run_rustc_version(&toolchain) {
-            RustupRunRustcVersionOutcome::RustcVersion(stdout) => {
-                format_rustc_version(config, stdout)
+            RustupRunRustcVersionOutcome::RustcVersion(rustc_version) => {
+                format_rustc_version(&rustc_version, config.version_format)
             }
-            RustupRunRustcVersionOutcome::ToolchainName(toolchain) => toolchain,
+            RustupRunRustcVersionOutcome::ToolchainName(toolchain) => Some(toolchain),
             RustupRunRustcVersionOutcome::RustupNotWorking => {
                 // If `rustup` is not in `$PATH` or cannot be executed for other reasons, we can
                 // safely execute `rustc --version`.
-                format_rustc_version(config, execute_rustc_version()?)
+                format_rustc_version(&execute_rustc_version()?, config.version_format)
             }
-            RustupRunRustcVersionOutcome::Err => return None,
+            RustupRunRustcVersionOutcome::Err => None,
         }
     } else {
-        format_rustc_version(config, execute_rustc_version()?)
-    };
-
-    Some(module_version)
+        format_rustc_version(&execute_rustc_version()?, config.version_format)
+    }
 }
 
 fn env_rustup_toolchain(context: &Context) -> Option<String> {
@@ -205,14 +203,19 @@ fn execute_rustc_version() -> Option<String> {
     }
 }
 
-fn format_rustc_version(config: &RustConfig, mut rustc_stdout: String) -> String {
-    let offset = &rustc_stdout.find('(').unwrap_or_else(|| rustc_stdout.len());
-    let formatted_version: String = rustc_stdout.drain(..offset).collect();
-    let full_version_string = formatted_version.replace("rustc", "");
-    let version_string = full_version_string.trim();
-    match VersionFormatter::new(config.version_format) {
-        Ok(formatter) => formatter.format_version(&version_string),
-        _ => format!("v{}", version_string),
+fn format_rustc_version(rustc_version: &str, version_format: &str) -> Option<String> {
+    let version = rustc_version
+        // split into ["rustc", "1.34.0", ...]
+        .split_whitespace()
+        // get down to "1.34.0"
+        .nth(1)?;
+
+    match VersionFormatter::format_version(version, version_format) {
+        Ok(formatted) => Some(formatted),
+        Err(error) => {
+            log::warn!("Error formating `rust` version:\n{}", error);
+            Some(format!("v{}", version))
+        }
     }
 }
 
@@ -326,27 +329,25 @@ mod tests {
 
     #[test]
     fn test_format_rustc_version() {
-        let test_config: RustConfig = RustConfig::default();
-
-        let nightly_input = String::from("rustc 1.34.0-nightly (b139669f3 2019-04-10)");
+        let config = RustConfig::default();
+        let rustc_stable = "rustc 1.34.0 (91856ed52 2019-04-10)";
+        let rustc_beta = "rustc 1.34.0-beta.1 (2bc1d406d 2019-04-10)";
+        let rustc_nightly = "rustc 1.34.0-nightly (b139669f3 2019-04-10)";
         assert_eq!(
-            format_rustc_version(&test_config, nightly_input),
-            "v1.34.0-nightly"
+            format_rustc_version(rustc_nightly, config.version_format),
+            Some("v1.34.0-nightly".to_string())
         );
-
-        let beta_input = String::from("rustc 1.34.0-beta.1 (2bc1d406d 2019-04-10)");
         assert_eq!(
-            format_rustc_version(&test_config, beta_input),
-            "v1.34.0-beta.1"
+            format_rustc_version(rustc_beta, config.version_format),
+            Some("v1.34.0-beta.1".to_string())
+        );
+        assert_eq!(
+            format_rustc_version(rustc_stable, config.version_format),
+            Some("v1.34.0".to_string())
         );
-
-        let stable_input = String::from("rustc 1.34.0 (91856ed52 2019-04-10)");
-        assert_eq!(format_rustc_version(&test_config, stable_input), "v1.34.0");
-
-        let version_without_hash = String::from("rustc 1.34.0");
         assert_eq!(
-            format_rustc_version(&test_config, version_without_hash),
-            "v1.34.0"
+            format_rustc_version("rustc 1.34.0", config.version_format),
+            Some("v1.34.0".to_string())
         );
     }