lib fix: do not permit out-of-plate destinations

plate-tool-lib/src/transfer_region.rs

@@ -250,24 +250,39 @@ impl TransferRegion {
 
         // Non-replicate transfers:
         match &self.dest_region {
-            Region::Point(Well { row: x, col: y }) => {
-                Box::new(move |Well { row: i, col: j }| {
-                    if source_wells.contains(&Well { row: i, col: j }) {
+            Region::Point(dest_point) => {
+                // Breaking from form somewhat, we really should return an entirely different
+                // function if a point-dest can't fit the whole source.
+                // If the bottom-right well of the source won't fit in the dest,
+                // we can abort.
+                let source_bottom_right = match self.source_region {
+                    Region::Point(x) => x,
+                    Region::Rect(w1, w2) => standardize_rectangle(&w1, &w2).1,
+                    Region::Custom(_) => unreachable!("A point destination region cannot be paired with a custom source destination?"),
+                };
+                let bottom_right_mapped = Self::point_destination_region_calc(
+                    source_bottom_right,
+                    source_ul,
+                    il_source,
+                    il_dest,
+                    *dest_point,
+                );
+                if bottom_right_mapped.row > self.dest_plate.plate_format.rows()
+                    || bottom_right_mapped.col > self.dest_plate.plate_format.columns()
+                {
+                    return Box::new(|_| None);
+                }
+
+                Box::new(move |input| {
+                    if source_wells.contains(&input) {
                         // Validity here already checked by self.validate()
-                        Some(vec![Well {
-                            row: x + i
-                                .checked_sub(source_ul.row)
-                                .expect("Point cannot have been less than UL")
-                                .checked_div(il_source.0.unsigned_abs())
-                                .expect("Source interleave cannot be 0")
-                                .mul(il_dest.0.unsigned_abs()),
-                            col: y + j
-                                .checked_sub(source_ul.col)
-                                .expect("Point cannot have been less than UL")
-                                .checked_div(il_source.1.unsigned_abs())
-                                .expect("Source interleave cannot be 0")
-                                .mul(il_dest.1.unsigned_abs()),
-                        }])
+                        Some(vec![Self::point_destination_region_calc(
+                            input,
+                            source_ul,
+                            il_source,
+                            il_dest,
+                            *dest_point,
+                        )])
                     } else {
                         None
                     }
@@ -387,6 +402,33 @@ impl TransferRegion {
         }
     }
 
+    fn point_destination_region_calc(
+        input: Well,
+        source_ul: Well,
+        il_source: (i8, i8),
+        il_dest: (i8, i8),
+        dest_point: Well,
+    ) -> Well {
+        Well {
+            row: dest_point.row
+                + input
+                    .row
+                    .checked_sub(source_ul.row)
+                    .expect("Point cannot have been less than UL")
+                    .checked_div(il_source.0.unsigned_abs())
+                    .expect("Source interleave cannot be 0")
+                    .mul(il_dest.0.unsigned_abs()),
+            col: dest_point.col
+                + input
+                    .col
+                    .checked_sub(source_ul.col)
+                    .expect("Point cannot have been less than UL")
+                    .checked_div(il_source.1.unsigned_abs())
+                    .expect("Source interleave cannot be 0")
+                    .mul(il_dest.1.unsigned_abs()),
+        }
+    }
+
     pub fn validate(&self) -> Result<(), &'static str> {
         // Checks if the region does anything suspect
         //
@@ -400,6 +442,12 @@ impl TransferRegion {
         let il_dest = self.interleave_dest;
 
         match self.source_region {
+            /*
+             * Note 04Jan2025:
+             *  I genuinely cannot think of a reason why we should need to validate a source
+             *  point region???
+             *  Like, why would it *not* be in the plate?
+             */
             Region::Point(_) => return Ok(()), // Should make sure it's actually in the plate, leave for
             // later
             Region::Rect(s1, s2) => {