1 files changed, 28 insertions, 12 deletions

diff --git a/src/map.rs b/src/map.rs
index be81216..671318e 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -1,12 +1,12 @@
-use std::error::Error;
 use textwrap::fill;
 
 pub use crate::from_yaml;
+pub use crate::RoadmapError;
 pub use crate::Status;
 pub use crate::Step;
 
 /// Error in Roadmap, from parsing or otherwise.
-pub type RoadmapResult<T> = Result<T, Box<dyn Error>>;
+pub type RoadmapResult<T> = Result<T, RoadmapError>;
 
 /// Represent a full project roadmap.
 ///
@@ -25,9 +25,17 @@ impl Roadmap {
         Roadmap { steps: vec![] }
     }
 
+    // Find steps that nothing depends on.
+    fn goals(&self) -> Vec<&Step> {
+        self.steps
+            .iter()
+            .filter(|step| self.is_goal(step))
+            .collect()
+    }
+
     /// Count number of steps that nothing depends on.
     pub fn count_goals(&self) -> usize {
-        self.steps.iter().filter(|step| self.is_goal(step)).count()
+        self.goals().len()
     }
 
     /// Iterate over step names.
@@ -120,21 +128,29 @@ impl Roadmap {
     // Validate that the parsed, constructed roadmap is valid.
     pub fn validate(&self) -> RoadmapResult<()> {
         // Is there exactly one goal?
-        match self.count_goals() {
-            0 => return Err(format!("the roadmap doesn't have a goal").into()),
+        let goals = self.goals();
+        let n = goals.len();
+        match n {
+            0 => return Err(RoadmapError::NoGoals),
             1 => (),
-            _ => return Err(format!("must have exactly one goal for roadmap").into()),
+            _ => {
+                let names: Vec<String> = goals.iter().map(|s| s.name().into()).collect();
+                return Err(RoadmapError::ManyGoals {
+                    count: n,
+                    names: names,
+                });
+            }
         }
 
         // Does every dependency exist?
         for step in self.iter() {
             for depname in step.dependencies() {
                 match self.get_step(depname) {
-                    None => {
-                        return Err(
-                            format!("step {} depends on missing {}", step.name(), depname).into(),
-                        )
-                    }
+                    None =>
+                        return Err(RoadmapError::MissingDep {
+                            name: step.name().into(),
+                            missing: depname.into(),
+                        }),
                     Some(_) => (),
                 }
             }
@@ -191,7 +207,7 @@ impl Roadmap {
     fn get_status_shape(step: &Step) -> &str {
         match step.status() {
             Status::Blocked => "rectangle",
-            Status::Finished => "circle",
+            Status::Finished => "octagon",
             Status::Ready => "ellipse",
             Status::Next => "ellipse",
             Status::Goal => "diamond",