Update Tag API (#19)

The `new` method allows users to construct tags pretty simply from
strings. And this isn't much trouble, but preserves the strong-typing
idea from Rust, requiring e.g., `t.add_tag(Tag("foo"))`.

src/task/tag.rs

@@ -1,17 +1,26 @@
-use pyo3::prelude::*;
+use pyo3::{exceptions::PyValueError, prelude::*};
 use taskchampion::Tag as TCTag;
 
-/// TODO: following the api there currently is no way to construct the task by hand, not sure if this is
-/// correct
 #[pyclass]
-pub struct Tag(pub(crate) TCTag);
+pub struct Tag(TCTag);
 
 #[pymethods]
 impl Tag {
     #[new]
-    pub fn new(tag: String) -> anyhow::Result<Self> {
-        Ok(Tag(tag.parse()?))
+    pub fn new(tag: String) -> PyResult<Self> {
+        Ok(Tag(tag
+            .parse()
+            .map_err(|_| PyValueError::new_err("Invalid tag"))?))
     }
+
+    pub fn __repr__(&self) -> String {
+        format!("{:?}", self.0)
+    }
+
+    pub fn __str__(&self) -> String {
+        self.0.to_string()
+    }
+
     pub fn is_synthetic(&self) -> bool {
         self.0.is_synthetic()
     }
@@ -21,6 +30,18 @@ impl Tag {
     }
 }
 
+impl AsRef<TCTag> for Tag {
+    fn as_ref(&self) -> &TCTag {
+        &self.0
+    }
+}
+
+impl From<TCTag> for Tag {
+    fn from(value: TCTag) -> Self {
+        Tag(value)
+    }
+}
+
 impl From<Tag> for TCTag {
     fn from(value: Tag) -> Self {
         value.0

src/task/task.rs

@@ -93,18 +93,16 @@ impl Task {
     ///
     /// Returns:
     ///     bool: if the task has a given tag
-    // TODO: Not very user friendly; User has to construct a Tag object and then pass is into here.
-    // Should probably use a string
     pub fn has_tag(&self, tag: &Tag) -> bool {
-        self.0.has_tag(&tag.0)
+        self.0.has_tag(tag.as_ref())
     }
 
     /// Get task tags
     ///
     /// Returns:
     ///     list[str]: list of tags
     pub fn get_tags(&self) -> Vec<Tag> {
-        self.0.get_tags().map(Tag).collect()
+        self.0.get_tags().map(Tag::from).collect()
     }
     /// Get task annotations
     ///
@@ -280,15 +278,15 @@ impl Task {
     pub fn add_tag(&mut self, tag: &Tag) -> anyhow::Result<Vec<Operation>> {
         let mut ops: Vec<TCOperation> = Vec::new();
 
-        self.0.add_tag(&tag.0, &mut ops).expect("");
+        self.0.add_tag(tag.as_ref(), &mut ops).expect("");
 
         Ok(ops.iter().map(|op| Operation(op.clone())).collect())
     }
 
     pub fn remove_tag(&mut self, tag: &Tag) -> anyhow::Result<Vec<Operation>> {
         let mut ops: Vec<TCOperation> = Vec::new();
 
-        self.0.remove_tag(&tag.0, &mut ops).expect("");
+        self.0.remove_tag(tag.as_ref(), &mut ops).expect("");
 
         Ok(ops.iter().map(|op| Operation(op.clone())).collect())
     }

tests/test_tag.py

@@ -12,6 +12,23 @@ def synthetic_tag():
     return Tag("UNBLOCKED")
 
 
+def test_invalid():
+    with pytest.raises(ValueError):
+        Tag("-24098")
+    with pytest.raises(ValueError):
+        Tag("FOO")
+
+
+def test_repr(user_tag, synthetic_tag):
+    assert repr(user_tag) == 'Tag(User("user_tag"))'
+    assert repr(synthetic_tag) == "Tag(Synthetic(Unblocked))"
+
+
+def test_str(user_tag, synthetic_tag):
+    assert str(user_tag) == "user_tag"
+    assert str(synthetic_tag) == "UNBLOCKED"
+
+
 def test_user_tag(user_tag: Tag):
     assert user_tag.is_user()
     assert not user_tag.is_synthetic()