fix: rustify build script

Author: hstove

stacks-common/build.rs

@@ -4,59 +4,48 @@ use std::{env, fs};
 
 use toml::Value;
 
-fn current_git_hash() -> Option<String> {
-    if option_env!("GIT_COMMIT") == None {
-        let commit = Command::new("git")
-            .arg("log")
-            .arg("-1")
-            .arg("--pretty=format:%h") // Abbreviated commit hash
-            .current_dir(env!("CARGO_MANIFEST_DIR"))
-            .output();
-
-        if let Ok(commit) = commit {
-            if let Ok(commit) = String::from_utf8(commit.stdout) {
-                return Some(commit.trim().to_string());
-            }
-        }
-    } else {
-        return option_env!("GIT_COMMIT").map(String::from);
-    }
+/// Given a [Command], run it and return the output as a string,
+/// returning `None` if the command fails.
+fn run_git_command(command: &mut Command) -> Option<String> {
+    command
+        .output()
+        .map(|output| String::from_utf8(output.stdout).ok())
+        .unwrap_or(None)
+        .map(|s| s.trim().to_string())
+}
 
-    None
+fn current_git_hash() -> Option<String> {
+    option_env!("GIT_COMMIT").map(String::from).or_else(|| {
+        run_git_command(
+            Command::new("git")
+                .arg("log")
+                .arg("-1")
+                .arg("--pretty=format:%h")
+                .current_dir(env!("CARGO_MANIFEST_DIR")),
+        )
+    })
 }
 
 fn current_git_branch() -> Option<String> {
-    if option_env!("GIT_BRANCH") == None {
-        let commit = Command::new("git")
-            .arg("rev-parse")
-            .arg("--abbrev-ref")
-            .arg("HEAD")
-            .output();
-        if let Ok(commit) = commit {
-            if let Ok(commit) = String::from_utf8(commit.stdout) {
-                return Some(commit.trim().to_string());
-            }
-        }
-    } else {
-        return option_env!("GIT_BRANCH").map(String::from);
-    }
-
-    None
+    option_env!("GIT_BRANCH").map(String::from).or_else(|| {
+        run_git_command(
+            Command::new("git")
+                .arg("rev-parse")
+                .arg("--abbrev-ref")
+                .arg("HEAD"),
+        )
+    })
 }
 
 fn is_working_tree_clean() -> bool {
-    let status = Command::new("git")
+    Command::new("git")
         .arg("diff")
         .arg("--quiet")
         .arg("--exit-code")
         .current_dir(env!("CARGO_MANIFEST_DIR"))
-        .status();
-
-    if let Ok(status) = status {
-        status.code() == Some(0)
-    } else {
-        true
-    }
+        .status()
+        .map(|status| status.code() == Some(0))
+        .unwrap_or(true)
 }
 
 fn main() {
@@ -90,40 +79,29 @@ fn main() {
         }
     }
 
-    if let Some(git) = current_git_hash() {
-        // println!("git commit: {}", git);
-        rust_code.push_str(&format!(
-            "pub const GIT_COMMIT: Option<&'static str> = Some(\"{}\");\n",
-            git
-        ));
-        println!("cargo:rustc-env=GIT_COMMIT={}", git);
-    } else {
-        rust_code.push_str(&format!(
-            "pub const GIT_COMMIT: Option<&'static str> = None;\n"
-        ));
-    }
-    if let Some(git) = current_git_branch() {
-        rust_code.push_str(&format!(
-            "pub const GIT_BRANCH: Option<&'static str> = Some(\"{}\");\n",
-            git
-        ));
-        println!("cargo:rustc-env=GIT_BRANCH={}", git);
-    } else {
-        rust_code.push_str(&format!(
-            "pub const GIT_BRANCH: Option<&'static str> = None;\n"
-        ));
+    let git_commit = current_git_hash();
+    rust_code.push_str(&format!(
+        "pub const GIT_COMMIT: Option<&'static str> = {git_commit:?};\n",
+    ));
+    if let Some(git_commit) = git_commit {
+        println!("cargo:rustc-env=GIT_COMMIT={}", git_commit);
     }
-    if !is_working_tree_clean() {
-        rust_code.push_str(&format!(
-            "pub const GIT_TREE_CLEAN: Option<&'static str> = Some(\"\");\n"
-        ));
-        println!("cargo:rustc-env=GIT_TREE_CLEAN=+");
-    } else {
-        rust_code.push_str(&format!(
-            "pub const GIT_TREE_CLEAN: Option<&'static str> = Some(\"+\");\n"
-        ));
+
+    let git_branch = current_git_branch();
+    rust_code.push_str(&format!(
+        "pub const GIT_BRANCH: Option<&'static str> = {git_branch:?};\n",
+    ));
+    if let Some(git_branch) = git_branch {
+        println!("cargo:rustc-env=GIT_BRANCH={}", git_branch);
     }
 
+    let is_clean = if is_working_tree_clean() { "" } else { "+" };
+    rust_code.push_str(&format!(
+        "pub const GIT_TREE_CLEAN: Option<&'static str> = Some(\"{}\");\n",
+        is_clean
+    ));
+    println!("cargo:rustc-env=GIT_TREE_CLEAN={}", is_clean);
+
     let out_dir = env::var_os("OUT_DIR").unwrap();
     let dest_path = Path::new(&out_dir).join("versions.rs");
     fs::write(&dest_path, rust_code).expect("Failed to write generated code");

stackslib/src/lib.rs

@@ -82,9 +82,9 @@ const BUILD_TYPE: &'static str = "release";
 
 pub fn version_string(pkg_name: &str, pkg_version: Option<&str>) -> String {
     let pkg_version = pkg_version.unwrap_or(STACKS_NODE_VERSION);
-    let git_branch = GIT_BRANCH_ENV.unwrap_or(GIT_BRANCH.unwrap_or(""));
-    let git_commit = GIT_COMMIT_ENV.unwrap_or(GIT_COMMIT.unwrap_or(""));
-    let git_tree_clean = GIT_TREE_CLEAN_ENV.unwrap_or(GIT_TREE_CLEAN.unwrap_or(""));
+    let git_branch = GIT_BRANCH_ENV.unwrap_or_else(|| GIT_BRANCH.unwrap_or(""));
+    let git_commit = GIT_COMMIT_ENV.unwrap_or_else(|| GIT_COMMIT.unwrap_or(""));
+    let git_tree_clean = GIT_TREE_CLEAN_ENV.unwrap_or_else(|| GIT_TREE_CLEAN.unwrap_or(""));
 
     format!(
         "{} {} ({}:{}{}, {} build, {} [{}])",