[FIX] mergeContiguousZones: add test & fix diagonal

This commit moves the tests of mergeContiguousZones from Odoo
to o-spreadsheet.

It also fixes a bug where the algorithm was merging zones that were
diagonal to each other.

closes #4332

Task: 3869372
Signed-off-by: Rémi Rahir (rar) <rar@odoo.com>

src/helpers/zones.ts

@@ -609,24 +609,21 @@ export function unionPositionsToZone(positions: Position[]): Zone {
  * Check if two zones are contiguous, ie. that they share a border
  */
 function areZoneContiguous(zone1: Zone, zone2: Zone) {
-  const u = union(zone1, zone2);
   if (zone1.right + 1 === zone2.left || zone1.left === zone2.right + 1) {
-    return getZoneHeight(u) <= getZoneHeight(zone1) + getZoneHeight(zone2);
+    return (
+      (zone1.top <= zone2.bottom && zone1.top >= zone2.top) ||
+      (zone2.top <= zone1.bottom && zone2.top >= zone1.top)
+    );
   }
   if (zone1.bottom + 1 === zone2.top || zone1.top === zone2.bottom + 1) {
-    return getZoneWidth(u) <= getZoneWidth(zone1) + getZoneWidth(zone2);
+    return (
+      (zone1.left <= zone2.right && zone1.left >= zone2.left) ||
+      (zone2.left <= zone1.right && zone2.left >= zone1.left)
+    );
   }
   return false;
 }
 
-function getZoneHeight(zone: Zone) {
-  return zone.bottom - zone.top + 1;
-}
-
-function getZoneWidth(zone: Zone) {
-  return zone.right - zone.left + 1;
-}
-
 /**
  * Merge contiguous and overlapping zones that are in the array into bigger zones
  */

tests/helpers/zones_helpers.test.ts

@@ -1,13 +1,17 @@
 import {
   createAdaptedZone,
   isZoneValid,
+  mergeContiguousZones,
   overlap,
   positions,
   toCartesian,
   toUnboundedZone,
   toZone,
+  zoneToXc,
 } from "../../src/helpers/index";
+
 import { Zone } from "../../src/types";
+import { target } from "../test_helpers/helpers";
 
 describe("overlap", () => {
   test("one zone above the other", () => {
@@ -153,3 +157,41 @@ describe("createAdaptedZone", () => {
     expect(createAdaptedZone(zone, "both", "RESIZE", [-1, -1])).toEqual(toZone("B2"));
   });
 });
+
+describe("mergeContiguousZones", () => {
+  test("mergeContiguousZones: can merge two contiguous zones", () => {
+    let zones = mergeContiguousZones(target("A1:A6, B1:B6"));
+    expect(zones.map(zoneToXc)).toEqual(["A1:B6"]);
+
+    zones = mergeContiguousZones(target("A1:D1, A2:D2"));
+    expect(zones.map(zoneToXc)).toEqual(["A1:D2"]);
+
+    zones = mergeContiguousZones(target("A1:A6, B2"));
+    expect(zones.map(zoneToXc)).toEqual(["A1:B6"]);
+
+    zones = mergeContiguousZones(target("C1, A2:F2"));
+    expect(zones.map(zoneToXc)).toEqual(["A1:F2"]);
+
+    // Not contiguous
+    zones = mergeContiguousZones(target("C1, C3"));
+    expect(zones.map(zoneToXc)).toEqual(["C1", "C3"]);
+  });
+
+  test("mergeContiguousZones: can merge two overlapping zones", () => {
+    let zones = mergeContiguousZones(target("A1:A6, A1:C4"));
+    expect(zones.map(zoneToXc)).toEqual(["A1:C6"]);
+
+    zones = mergeContiguousZones(target("A1:C6, A1:B5"));
+    expect(zones.map(zoneToXc)).toEqual(["A1:C6"]);
+  });
+
+  test("mergeContiguousZones: can merge overlapping and contiguous zones", () => {
+    const zones = mergeContiguousZones(target("A1:A6, A1:C4, A7"));
+    expect(zones.map(zoneToXc)).toEqual(["A1:C7"]);
+  });
+
+  test("Zones diagonally next to each other are not contiguous", () => {
+    const zones = mergeContiguousZones(target("A1, B2, C3, A3"));
+    expect(zones.map(zoneToXc)).toEqual(["A1", "B2", "C3", "A3"]);
+  });
+});