3 files changed, 84 insertions, 1 deletions
diff --git a/lib/valueLimits.js b/lib/valueLimits.js
new file mode 100644
index 0000000..c902883
--- /dev/null
+++ b/lib/valueLimits.js
@@ -0,0 +1,17 @@
+/**
+ * In OSM tag values are limited to 255 characters.
+ * Search for addr:flats beyond that limit and wrap into addr:flats2 addr:flats3 etc.
+ * 
+ * @param {Object} feature 
+ * @returns {boolean}
+ */
+module.exports = (feature) => {
+  if ('addr:flats' in feature.properties && feature.properties['addr:flats'].length > 255) {
+    // need to wrap
+    const value = feature.properties['addr:flats']
+    for (let i = 0; i < value.length; i += 255) {
+      feature.properties[`addr:flats${i === 0 ? '' : i / 255 + 1}`] = value.slice(i, i + 255)
+    }
+  }
+  return feature
+}
diff --git a/package.json b/package.json
index 825e344..388427e 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,7 @@
   "author": "Andrew Harvey <andrew@alantgeo.com.au>",
   "license": "MIT",
   "scripts": {
-    "test": "./node_modules/.bin/tape test/toOSM.js test/cluster.js test/unitsToRanges.js test/withinRange.js"
+    "test": "./node_modules/.bin/tape test/toOSM.js test/cluster.js test/unitsToRanges.js test/withinRange.js test/valueLimits.js"
   },
   "dependencies": {
     "capital-case": "^1.0.4",
diff --git a/test/valueLimits.js b/test/valueLimits.js
new file mode 100644
index 0000000..a7f7fd7
--- /dev/null
+++ b/test/valueLimits.js
@@ -0,0 +1,66 @@
+const test = require('tape')
+
+const valueLimits = require('../lib/valueLimits.js')
+
+test('less than limit', t => {
+  t.same(
+    valueLimits({
+      properties: {
+        'addr:flats': ''
+      }
+    }),
+    {
+      properties: {
+        'addr:flats': ''
+      }
+    },
+    'less than limit'
+  )
+
+  t.same(
+    valueLimits({
+      properties: {
+        'addr:flats': '#'.repeat(255)
+      }
+    }),
+    {
+      properties: {
+        'addr:flats': '#'.repeat(255)
+      }
+    },
+    'exactly at limit'
+  )
+
+  t.same(
+    valueLimits({
+      properties: {
+        'addr:flats': '#'.repeat(256)
+      }
+    }),
+    {
+      properties: {
+        'addr:flats': '#'.repeat(255),
+        'addr:flats2': '#'.repeat(1)
+      }
+    },
+    'one over limit'
+  )
+
+  t.same(
+    valueLimits({
+      properties: {
+        'addr:flats': '#'.repeat(255 + 255 + 100)
+      }
+    }),
+    {
+      properties: {
+        'addr:flats': '#'.repeat(255),
+        'addr:flats2': '#'.repeat(255),
+        'addr:flats3': '#'.repeat(100)
+      }
+    },
+    'split into three'
+  )
+
+  t.end()
+})