Clarify git credential code and fix infinite loop bug (#898)

Fixes #897

crates/bin/src/args.rs

@@ -1,7 +1,7 @@
 use std::{
     env,
     ffi::OsString,
-    fmt, fs, iter,
+    fmt,
     num::{NonZeroU64, ParseIntError},
     path::PathBuf,
     str::FromStr,
@@ -14,7 +14,7 @@ use binstalk::{
 };
 use clap::{error::ErrorKind, CommandFactory, Parser, ValueEnum};
 use compact_str::CompactString;
-use dirs::home_dir;
+
 use log::LevelFilter;
 use semver::VersionReq;
 use strum::EnumCount;
@@ -473,7 +473,7 @@ You cannot use --{option} and specify multiple packages at the same time. Do one
         if let Ok(github_token) = env::var("GH_TOKEN") {
             opts.github_token = Some(github_token.into());
         } else if !opts.no_discover_github_token {
-            if let Some(github_token) = try_extract_from_git_credentials() {
+            if let Some(github_token) = crate::git_credentials::try_from_home() {
                 opts.github_token = Some(github_token);
             } else if let Ok(github_token) = gh_token::get() {
                 opts.github_token = Some(github_token.into());
@@ -484,41 +484,6 @@ You cannot use --{option} and specify multiple packages at the same time. Do one
     opts
 }
 
-fn try_extract_from_git_credentials() -> Option<CompactString> {
-    home_dir()
-        .map(|mut home| {
-            home.push(".git-credentials");
-            home
-        })
-        .into_iter()
-        .chain(iter::from_fn(|| {
-            let home = env::var_os("XDG_CONFIG_HOME")?;
-            (!home.is_empty()).then(|| {
-                let mut path = PathBuf::from(home);
-                path.push("git/credentials");
-                path
-            })
-        }))
-        .find_map(try_extract_from_git_credentials_from)
-}
-
-fn try_extract_from_git_credentials_from(path: PathBuf) -> Option<CompactString> {
-    fs::read_to_string(path)
-        .ok()?
-        .lines()
-        .find_map(extract_github_token_from_git_credentials_line)
-        .map(CompactString::from)
-}
-
-fn extract_github_token_from_git_credentials_line(line: &str) -> Option<&str> {
-    let cred = line
-        .trim()
-        .strip_prefix("https://")?
-        .strip_suffix("@github.com")?;
-
-    Some(cred.split_once(':')?.1)
-}
-
 #[cfg(test)]
 mod test {
     use super::*;
@@ -527,24 +492,4 @@ mod test {
     fn verify_cli() {
         Args::command().debug_assert()
     }
-
-    const GIT_CREDENTIALS_TEST_CASES: &[(&str, Option<&str>)] = &[
-        // Success
-        ("https://NobodyXu:gho_asdc@github.com", Some("gho_asdc")),
-        (
-            "https://NobodyXu:gho_asdc12dz@github.com",
-            Some("gho_asdc12dz"),
-        ),
-        // Failure
-        ("http://NobodyXu:gho_asdc@github.com", None),
-        ("https://NobodyXu:gho_asdc@gitlab.com", None),
-        ("https://NobodyXugho_asdc@github.com", None),
-    ];
-
-    #[test]
-    fn test_extract_github_token_from_git_credentials_line() {
-        GIT_CREDENTIALS_TEST_CASES.iter().for_each(|(line, res)| {
-            assert_eq!(extract_github_token_from_git_credentials_line(line), *res);
-        })
-    }
 }

crates/bin/src/git_credentials.rs

@@ -0,0 +1,67 @@
+use std::{
+    env, fs,
+    path::{Path, PathBuf},
+};
+
+use compact_str::CompactString;
+use dirs::home_dir;
+
+pub fn try_from_home() -> Option<CompactString> {
+    if let Some(mut home) = home_dir() {
+        home.push(".git-credentials");
+        if let Some(cred) = from_file(home) {
+            return Some(cred);
+        }
+    }
+
+    if let Some(home) = env::var_os("XDG_CONFIG_HOME") {
+        let home = Path::new(&home).join("git/credentials");
+        if let Some(cred) = from_file(home) {
+            return Some(cred);
+        }
+    }
+
+    None
+}
+
+fn from_file(path: PathBuf) -> Option<CompactString> {
+    fs::read_to_string(path)
+        .ok()?
+        .lines()
+        .find_map(from_line)
+        .map(CompactString::from)
+}
+
+fn from_line(line: &str) -> Option<&str> {
+    let cred = line
+        .trim()
+        .strip_prefix("https://")?
+        .strip_suffix("@github.com")?;
+
+    Some(cred.split_once(':')?.1)
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    const GIT_CREDENTIALS_TEST_CASES: &[(&str, Option<&str>)] = &[
+        // Success
+        ("https://NobodyXu:gho_asdc@github.com", Some("gho_asdc")),
+        (
+            "https://NobodyXu:gho_asdc12dz@github.com",
+            Some("gho_asdc12dz"),
+        ),
+        // Failure
+        ("http://NobodyXu:gho_asdc@github.com", None),
+        ("https://NobodyXu:gho_asdc@gitlab.com", None),
+        ("https://NobodyXugho_asdc@github.com", None),
+    ];
+
+    #[test]
+    fn test_extract_from_line() {
+        GIT_CREDENTIALS_TEST_CASES.iter().for_each(|(line, res)| {
+            assert_eq!(from_line(line), *res);
+        })
+    }
+}

crates/bin/src/lib.rs

@@ -1,6 +1,7 @@
 pub mod args;
 pub mod bin_util;
 pub mod entry;
+pub mod git_credentials;
 pub mod install_path;
 pub mod logging;
 pub mod manifests;