implemented unit tests for variable parameter expansions. currently all green

src/tests/expand.rs

@@ -1,5 +1,7 @@
 use std::collections::HashSet;
 
+use crate::expand::perform_param_expansion;
+
 use super::*;
 
 #[test]
@@ -122,3 +124,179 @@ fn test_infinite_recursive_alias() {
 	});
 
 }
+
+#[test]
+fn param_expansion_defaultunsetornull() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+        v.set_var("set_var", "value", false);
+    });
+    let result = perform_param_expansion("unset:-default").unwrap();
+    assert_eq!(result, "default");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_defaultunset() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+        v.set_var("set_var", "value", false);
+    });
+    let result = perform_param_expansion("unset-default").unwrap();
+    assert_eq!(result, "default");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_setdefaultunsetornull() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+        v.set_var("set_var", "value", false);
+    });
+    let result = perform_param_expansion("unset:=assigned").unwrap();
+    assert_eq!(result, "assigned");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_setdefaultunset() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+        v.set_var("set_var", "value", false);
+    });
+    let result = perform_param_expansion("unset=assigned").unwrap();
+    assert_eq!(result, "assigned");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_altsetnotnull() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+        v.set_var("set_var", "value", false);
+    });
+    let result = perform_param_expansion("set_var:+alt").unwrap();
+    assert_eq!(result, "alt");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_altnotnull() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+        v.set_var("set_var", "value", false);
+    });
+    let result = perform_param_expansion("set_var+alt").unwrap();
+    assert_eq!(result, "alt");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_len() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("#foo").unwrap();
+    assert_eq!(result, "3");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_substr() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo:1").unwrap();
+    assert_eq!(result, "oo");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_substrlen() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo:0:2").unwrap();
+    assert_eq!(result, "fo");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_remshortestprefix() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo#f*").unwrap();
+    assert_eq!(result, "oo");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_remlongestprefix() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo##f*").unwrap();
+    assert_eq!(result, "");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_remshortestsuffix() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo%*o").unwrap();
+    assert_eq!(result, "fo");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_remlongestsuffix() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo%%*o").unwrap();
+    assert_eq!(result, "");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_replacefirstmatch() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo/foo/X").unwrap();
+    assert_eq!(result, "X");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_replaceallmatches() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo//o/X").unwrap();
+    assert_eq!(result, "fXX");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_replaceprefix() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo/#f/X").unwrap();
+    assert_eq!(result, "Xoo");
+    write_vars(|v| v.vars_mut().clear());
+}
+
+#[test]
+fn param_expansion_replacesuffix() {
+    write_vars(|v| {
+        v.set_var("foo", "foo", false);
+    });
+    let result = perform_param_expansion("foo/%o/X").unwrap();
+    assert_eq!(result, "foX");
+    write_vars(|v| v.vars_mut().clear());
+}