Change: implement Roadmap::as_dot

1 files changed, 36 insertions, 11 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 760b0d2..e1d7b49 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -12,22 +12,28 @@
 //! # use roadmap::Step;
 //! # fn main() -> std::result::Result<(), Box<dyn std::error::Error>> {
 //! let mut r = roadmap::Roadmap::new();
-//! assert_eq!(r.steps().len(), 0);
+//! assert_eq!(r.step_names().len(), 0);
 //!
-//! let endgoal = roadmap::Step::new("endgoal", "the end goal");
+//! let mut endgoal = roadmap::Step::new("endgoal", "the end goal");
+//! endgoal.add_dependency("first");
 //! assert_eq!(endgoal.name(), "endgoal");
 //! assert_eq!(endgoal.label(), "the end goal");
-//! r.add_step(&endgoal)?;
-//! assert_eq!(r.steps().len(), 1);
+//! assert_eq!(endgoal.dependencies(), vec!["first"]);
 //!
 //! let first = roadmap::Step::new("first", "the first step");
+//!
+//!
+//! r.add_step(&endgoal)?;
+//! assert_eq!(r.step_names().len(), 1);
 //! r.add_step(&first)?;
-//! assert_eq!(r.steps().len(), 2);
+//! assert_eq!(r.step_names().len(), 2);
 //!
-//! if let Some(step) = r.get_step("endgoal") {
-//!     step.add_dependency("first");
-//!     assert_eq!(endgoal.dependencies(), vec!["first"]);
+//! assert_eq!(r.as_dot()?, r#"digraph "roadmap" {
+//! endgoal [label="the end goal"];
+//! first [label="the first step"];
+//! first -> endgoal;
 //! }
+//! "#.to_string());
 //! # Ok(())
 //! # }
 //! ```
@@ -61,7 +67,7 @@ impl Step {
     }
 
     /// Return vector of names of dependencies for a step.
-    pub fn dependencies(self) -> Vec<String> {
+    pub fn dependencies(&self) -> Vec<String> {
         self.depends.clone()
     }
 
@@ -88,7 +94,7 @@ impl Roadmap {
     }
 
     /// Return list of step names.
-    pub fn steps<'a>(&'a self) -> Vec<&'a str> {
+    pub fn step_names<'a>(&'a self) -> Vec<&'a str> {
         let mut names = vec![];
         for step in self.steps.iter() {
             names.push(step.name());
@@ -112,6 +118,25 @@ impl Roadmap {
     /// is the textual representation, and the caller needs to use the
     /// Graphviz dot(1) tool to create an image from it.
     pub fn as_dot(self) -> Result<String, Box<dyn std::error::Error>> {
-        Ok("".to_string())
+        let labels = self.steps.iter().map(|step|
+            format!("{} [label=\"{}\"];\n", step.name(), step.label())
+        );
+
+        let mut dot = String::new();
+        dot.push_str("digraph \"roadmap\" {\n");
+        for line in labels {
+            dot.push_str(&line);
+        }
+
+        for step in self.steps.iter() {
+            for dep in step.dependencies() {
+                let line = format!("{} -> {};\n", dep, step.name());
+                dot.push_str(&line);
+            }
+        }
+
+        dot.push_str("}\n");
+
+        Ok(dot)
     }
 }