62

src/ops.rs

@@ -22,7 +22,7 @@ use crate::Edge;
 use crate::Hex;
 use crate::Sodg;
 use crate::Vertex;
-use anyhow::{Context, Result};
+use anyhow::{anyhow, Context, Result};
 use log::trace;
 use rstest::rstest;
 
@@ -106,7 +106,13 @@ impl Sodg {
             .vertices
             .get_mut(&v)
             .context(format!("Can't find ν{v}"))?;
+        if vtx.posted {
+            return Err(anyhow!(
+                "The vertex isn't available, #put() was called earlier"
+            ));
+        }
         vtx.data = d.clone();
+        vtx.posted = true;
         self.validate(vec![v])?;
         trace!("#data: data of ν{v} set to {d}");
         Ok(())
@@ -475,3 +481,18 @@ fn checks_for_data_absence() -> Result<()> {
     assert!(!g.full(0).unwrap());
     Ok(())
 }
+
+#[test]
+fn checks_for_put_called_once() -> Result<()> {
+    let mut g = Sodg::empty();
+    g.add(0)?;
+    g.add(1)?;
+    g.bind(0, 1, "bar/baz")?;
+    g.put(0, Hex::from(42))?;
+    let actual = g.put(0, Hex::from(42)).unwrap_err();
+    assert_eq!(
+        format!("{}", actual.root_cause()),
+        "The vertex isn't available, #put() was called earlier"
+    );
+    Ok(())
+}

src/vertex.rs

@@ -28,6 +28,7 @@ pub(crate) struct Vertex {
     pub data: Hex,
     pub parents: HashSet<u32>,
     pub taken: bool,
+    pub posted: bool,
 }
 
 impl Vertex {
@@ -46,6 +47,7 @@ impl Vertex {
             data: Hex::empty(),
             parents: HashSet::new(),
             taken: false,
+            posted: false,
         }
     }
 }