added unit testing, and started implementing unit tests...phew

node_modules/fast-safe-stringify/index.js

@@ -0,0 +1,103 @@
+module.exports = stringify
+stringify.default = stringify
+stringify.stable = deterministicStringify
+stringify.stableStringify = deterministicStringify
+
+var arr = []
+
+// Regular stringify
+function stringify (obj, replacer, spacer) {
+  decirc(obj, '', [], undefined)
+  var res = JSON.stringify(obj, replacer, spacer)
+  while (arr.length !== 0) {
+    var part = arr.pop()
+    part[0][part[1]] = part[2]
+  }
+  return res
+}
+function decirc (val, k, stack, parent) {
+  var i
+  if (typeof val === 'object' && val !== null) {
+    for (i = 0; i < stack.length; i++) {
+      if (stack[i] === val) {
+        parent[k] = '[Circular]'
+        arr.push([parent, k, val])
+        return
+      }
+    }
+    stack.push(val)
+    // Optimize for Arrays. Big arrays could kill the performance otherwise!
+    if (Array.isArray(val)) {
+      for (i = 0; i < val.length; i++) {
+        decirc(val[i], i, stack, val)
+      }
+    } else {
+      var keys = Object.keys(val)
+      for (i = 0; i < keys.length; i++) {
+        var key = keys[i]
+        decirc(val[key], key, stack, val)
+      }
+    }
+    stack.pop()
+  }
+}
+
+// Stable-stringify
+function compareFunction (a, b) {
+  if (a < b) {
+    return -1
+  }
+  if (a > b) {
+    return 1
+  }
+  return 0
+}
+
+function deterministicStringify (obj, replacer, spacer) {
+  var tmp = deterministicDecirc(obj, '', [], undefined) || obj
+  var res = JSON.stringify(tmp, replacer, spacer)
+  while (arr.length !== 0) {
+    var part = arr.pop()
+    part[0][part[1]] = part[2]
+  }
+  return res
+}
+
+function deterministicDecirc (val, k, stack, parent) {
+  var i
+  if (typeof val === 'object' && val !== null) {
+    for (i = 0; i < stack.length; i++) {
+      if (stack[i] === val) {
+        parent[k] = '[Circular]'
+        arr.push([parent, k, val])
+        return
+      }
+    }
+    if (typeof val.toJSON === 'function') {
+      return
+    }
+    stack.push(val)
+    // Optimize for Arrays. Big arrays could kill the performance otherwise!
+    if (Array.isArray(val)) {
+      for (i = 0; i < val.length; i++) {
+        deterministicDecirc(val[i], i, stack, val)
+      }
+    } else {
+      // Create a temporary object in the required way
+      var tmp = {}
+      var keys = Object.keys(val).sort(compareFunction)
+      for (i = 0; i < keys.length; i++) {
+        var key = keys[i]
+        deterministicDecirc(val[key], key, stack, val)
+        tmp[key] = val[key]
+      }
+      if (parent !== undefined) {
+        arr.push([parent, k, val])
+        parent[k] = tmp
+      } else {
+        return tmp
+      }
+    }
+    stack.pop()
+  }
+}