Implement `build_alias`

Copy of the functionality in W. Caleb McDaniel's Bash script implemented
in Rust:

    echo "${MESSAGE}" | grep ^"From: " | sed s/[\,\"\']//g | awk '{$1=""; if (NF == 3) {print "alias" $0;} else if (NF == 2) {print "alias" $0 $0;} else if (NF > 3) {print "alias", tolower($(NF-1))"-"tolower($2) $0;}}'

Doesn't currently include the [,"'] filtering.

Added a couple of new test cases to cover other address formats.

Not sure if I should use `if..else if` here or a `match`. I feel like I
should return an empty string at the end if we can't build an alias
line.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/tests.rs b/src/tests.rs
index 20bbcc5..eff385a 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -3,6 +3,16 @@ use super::build_alias;
 #[test]
 fn test_build_alias() {
     assert_eq!(
+        "alias producer@765pro.ductions producer@765pro.ductions",
+        build_alias("From: producer@765pro.ductions")
+    );
+
+    assert_eq!(
+        "alias decim Decim <decim@quindecim.jp>",
+        build_alias("From: Decim <decim@quindecim.jp>")
+    );
+
+    assert_eq!(
         "alias farnsworth-hubert Hubert Farnsworth <professor@planetexpress.com>",
         build_alias("From: Hubert Farnsworth <professor@planetexpress.com>")
     );