Handle modifying rc files that don't have a trailing newline

src/cli/self_update/unix.rs

@@ -83,14 +83,20 @@ pub fn do_remove_from_path() -> Result<()> {
 pub fn do_add_to_path() -> Result<()> {
     for sh in shell::get_available_shells() {
         let source_cmd = sh.source_string()?;
+        let source_cmd_with_newline = format!("\n{}", &source_cmd);
+
         for rc in sh.update_rcs() {
-            if !rc.is_file() || !utils::read_file("rcfile", &rc)?.contains(&source_cmd) {
-                utils::append_file("rcfile", &rc, &source_cmd).chain_err(|| {
-                    ErrorKind::WritingShellProfile {
-                        path: rc.to_path_buf(),
-                    }
-                })?;
-            }
+            let cmd_to_write = match utils::read_file("rcfile", &rc) {
+                Ok(contents) if contents.contains(&source_cmd) => continue,
+                Ok(contents) if !contents.ends_with('\n') => &source_cmd_with_newline,
+                _ => &source_cmd,
+            };
+
+            utils::append_file("rcfile", &rc, &cmd_to_write).chain_err(|| {
+                ErrorKind::WritingShellProfile {
+                    path: rc.to_path_buf(),
+                }
+            })?;
         }
     }
 

tests/cli-paths.rs

@@ -157,6 +157,47 @@ export PATH="$HOME/apple/bin"
         });
     }
 
+    #[test]
+    fn install_adds_path_to_rc_handling_no_newline() {
+        clitools::setup(Scenario::Empty, &|config| {
+            let profile = config.homedir.join(".profile");
+            let fake_rc_modified = FAKE_RC.strip_suffix('\n').expect("Should end in a newline");
+            raw::write_file(&profile, fake_rc_modified).unwrap();
+            // Run once to to add the configuration
+            expect_ok(config, &INIT_NONE);
+            // Run twice to test that the process is idempotent
+            expect_ok(config, &INIT_NONE);
+
+            let new_profile = fs::read_to_string(&profile).unwrap();
+            let expected = FAKE_RC.to_owned() + &source(config.cargodir.display(), POSIX_SH);
+            assert_eq!(new_profile, expected);
+        });
+    }
+
+    #[test]
+    fn install_adds_path_to_multiple_rc_files() {
+        clitools::setup(Scenario::Empty, &|config| {
+            // Two RC files that are both from the same shell
+            let bash_profile = config.homedir.join(".bash_profile");
+            let bashrc = config.homedir.join(".bashrc");
+
+            let expected = FAKE_RC.to_owned() + &source(config.cargodir.display(), POSIX_SH);
+
+            // The order that the two files are processed isn't known, so test both orders
+            for [path1, path2] in &[[&bash_profile, &bashrc], [&bashrc, &bash_profile]] {
+                raw::write_file(&path1, &expected).unwrap();
+                raw::write_file(&path2, FAKE_RC).unwrap();
+
+                expect_ok(config, &INIT_NONE);
+
+                let new1 = fs::read_to_string(&path1).unwrap();
+                assert_eq!(new1, expected);
+                let new2 = fs::read_to_string(&path2).unwrap();
+                assert_eq!(new2, expected);
+            }
+        });
+    }
+
     #[test]
     fn uninstall_removes_source_from_rcs() {
         clitools::setup(Scenario::Empty, &|config| {