add cluster library

1 files changed, 83 insertions, 0 deletions

diff --git a/test/cluster.js b/test/cluster.js
new file mode 100644
index 0000000..ddec552
--- /dev/null
+++ b/test/cluster.js
@@ -0,0 +1,83 @@
+const test = require('tape')
+
+const cluster = require('../cluster.js')
+
+const A = {
+  type: 'Feature',
+  id: 'A',
+  properties: {},
+  geometry: {
+    type: 'Point',
+    coordinates: [0, 0]
+  }
+}
+
+const B = {
+  type: 'Feature',
+  id: 'B',
+  properties: {},
+  geometry: {
+    type: 'Point',
+    coordinates: [0, 0]
+  }
+}
+
+const C = {
+  type: 'Feature',
+  id: 'C',
+  properties: {},
+  geometry: {
+    type: 'Point',
+    coordinates: [0.000001, 0.000001]
+  }
+}
+
+const D = {
+  type: 'Feature',
+  id: 'D',
+  properties: {},
+  geometry: {
+    type: 'Point',
+    coordinates: [1, 1]
+  }
+}
+
+test('cluster', t => {
+  t.same(
+    cluster([], 100),
+    [],
+    'empty input returns empty output'
+  )
+
+  t.same(
+    cluster([A], 100),
+    [[A]],
+    'single feature input returns single feature output cluster'
+  )
+
+  t.same(
+    cluster([A, B], 100),
+    [[A, B]],
+    'overlapping points clustered'
+  )
+
+  t.same(
+    cluster([A, C], 100),
+    [[A, C]],
+    'nearby points clustered'
+  )
+
+  t.same(
+    cluster([A, D], 100),
+    [[A], [D]],
+    'far away points not clustered'
+  )
+
+  t.same(
+    cluster([A, B, C, D], 100),
+    [[A, B, C], [D]],
+    'some clustered others not'
+  )
+
+  t.end()
+})