Add: function to parse a scenario step

1 files changed, 54 insertions, 0 deletions

diff --git a/src/steps.rs b/src/steps.rs
index ca9a75c..ce1c031 100644
--- a/src/steps.rs
+++ b/src/steps.rs
@@ -27,6 +27,27 @@ impl ScenarioStep {
     pub fn text(&self) -> &str {
         &self.text
     }
+
+    pub fn from_str(text: &str) -> Option<ScenarioStep> {
+        let mut words = text.split_whitespace();
+
+        let kind = match words.next() {
+            Some("given") => StepKind::Given,
+            Some("when") => StepKind::When,
+            Some("then") => StepKind::Then,
+            _ => return None,
+        };
+
+        let mut joined = String::new();
+        for word in words {
+            joined.push_str(word);
+            joined.push_str(" ");
+        }
+        if joined.len() > 1 {
+            joined.pop();
+        }
+        Some(ScenarioStep::new(kind, &joined))
+    }
 }
 
 /// The kind of scenario step we have: given, when, or then.
@@ -40,3 +61,36 @@ pub enum StepKind {
     When,
     Then,
 }
+
+#[cfg(test)]
+mod test {
+    use super::{ScenarioStep, StepKind};
+
+    #[test]
+    fn parses_given() {
+        let step = ScenarioStep::from_str("given I am Tomjon").unwrap();
+        assert_eq!(step.kind(), StepKind::Given);
+        assert_eq!(step.text(), "I am Tomjon");
+    }
+
+    #[test]
+    fn parses_given_with_extra_spaces() {
+        let step = ScenarioStep::from_str("   given     I   am   Tomjon   ").unwrap();
+        assert_eq!(step.kind(), StepKind::Given);
+        assert_eq!(step.text(), "I am Tomjon");
+    }
+
+    #[test]
+    fn parses_when() {
+        let step = ScenarioStep::from_str("when I declare myself king").unwrap();
+        assert_eq!(step.kind(), StepKind::When);
+        assert_eq!(step.text(), "I declare myself king");
+    }
+
+    #[test]
+    fn parses_then() {
+        let step = ScenarioStep::from_str("then everyone accepts it").unwrap();
+        assert_eq!(step.kind(), StepKind::Then);
+        assert_eq!(step.text(), "everyone accepts it");
+    }
+}