Add ability to diff zones generated from current config against latest release

Fixes #83

1 files changed, 25 insertions, 0 deletions

diff --git a/util/featureWriterStream.js b/util/featureWriterStream.js
new file mode 100644
index 0000000..7f0e7b8
--- /dev/null
+++ b/util/featureWriterStream.js
@@ -0,0 +1,25 @@
+const fs = require('fs')
+
+class FeatureWriterStream {
+  constructor (file) {
+    this.file = file
+    this.stream = fs.createWriteStream(file)
+    this.stream.write('{"type":"FeatureCollection","features":[')
+    this.numFeatures = 0
+  }
+
+  add (stringifiedFeature) {
+    if (this.numFeatures > 0) {
+      this.stream.write(',')
+    }
+    this.stream.write(stringifiedFeature)
+    this.numFeatures++
+  }
+
+  end (cb) {
+    console.log(`Closing out file ${this.file}`)
+    this.stream.end(']}', cb)
+  }
+}
+
+module.exports = FeatureWriterStream