refactor(database): classes for typescript database implementation (#55)

* refactor(database): classes for typescript database implementation

* refactor(database): requested changes & other improvements

Author: jsayol

src/database/api/DataSnapshot.ts

@@ -1,187 +1,177 @@
-import { validateArgCount, validateCallback } from "../../utils/validation";
-import { validatePathString } from "../core/util/validation";
-import { Path } from "../core/util/Path";
-import { exportPropGetter } from "../core/util/util";
-import { PRIORITY_INDEX } from "../core/snap/indexes/PriorityIndex";
+import { validateArgCount, validateCallback } from '../../utils/validation';
+import { validatePathString } from '../core/util/validation';
+import { Path } from '../core/util/Path';
+import { PRIORITY_INDEX } from '../core/snap/indexes/PriorityIndex';
+import { Node } from '../core/snap/Node';
+import { Reference } from './Reference';
+import { Index } from '../core/snap/indexes/Index';
+import { ChildrenNode } from '../core/snap/ChildrenNode';
 
 /**
  * Class representing a firebase data snapshot.  It wraps a SnapshotNode and
  * surfaces the public methods (val, forEach, etc.) we want to expose.
- *
- * @constructor
- * @param {!fb.core.snap.Node} node A SnapshotNode to wrap.
- * @param {!Firebase} ref The ref of the location this snapshot came from.
- * @param {!fb.core.snap.Index} index The iteration order for this snapshot
  */
-export const DataSnapshot = function(node, ref, index) {
+export class DataSnapshot {
   /**
-   * @private
-   * @const
-   * @type {!fb.core.snap.Node}
+   * @param {!Node} node_ A SnapshotNode to wrap.
+   * @param {!Reference} ref_ The ref of the location this snapshot came from.
+   * @param {!Index} index_ The iteration order for this snapshot
    */
-  this.node_ = node;
+  constructor(private readonly node_: Node,
+              private readonly ref_: Reference,
+              private readonly index_: Index) {
+  }
 
   /**
-   * @private
-   * @type {!Firebase}
-   * @const
+   * Retrieves the snapshot contents as JSON.  Returns null if the snapshot is
+   * empty.
+   *
+   * @return {*} JSON representation of the DataSnapshot contents, or null if empty.
    */
-  this.query_ = ref;
+  val(): any {
+    validateArgCount('DataSnapshot.val', 0, 0, arguments.length);
+    return this.node_.val();
+  }
 
   /**
-   * @const
-   * @type {!fb.core.snap.Index}
-   * @private
+   * Returns the snapshot contents as JSON, including priorities of node.  Suitable for exporting
+   * the entire node contents.
+   * @return {*} JSON representation of the DataSnapshot contents, or null if empty.
    */
-  this.index_ = index;
-};
+  exportVal(): any {
+    validateArgCount('DataSnapshot.exportVal', 0, 0, arguments.length);
+    return this.node_.val(true);
+  }
+
+  // Do not create public documentation. This is intended to make JSON serialization work but is otherwise unnecessary
+  // for end-users
+  toJSON(): any {
+    // Optional spacer argument is unnecessary because we're depending on recursion rather than stringifying the content
+    validateArgCount('DataSnapshot.toJSON', 0, 1, arguments.length);
+    return this.exportVal();
+  }
 
+  /**
+   * Returns whether the snapshot contains a non-null value.
+   *
+   * @return {boolean} Whether the snapshot contains a non-null value, or is empty.
+   */
+  exists(): boolean {
+    validateArgCount('DataSnapshot.exists', 0, 0, arguments.length);
+    return !this.node_.isEmpty();
+  }
 
-/**
- * Retrieves the snapshot contents as JSON.  Returns null if the snapshot is
- * empty.
- *
- * @return {*} JSON representation of the DataSnapshot contents, or null if empty.
- */
-DataSnapshot.prototype.val = function() {
-  validateArgCount('Firebase.DataSnapshot.val', 0, 0, arguments.length);
-  return this.node_.val();
-};
-
-/**
- * Returns the snapshot contents as JSON, including priorities of node.  Suitable for exporting
- * the entire node contents.
- * @return {*} JSON representation of the DataSnapshot contents, or null if empty.
- */
-DataSnapshot.prototype.exportVal = function() {
-  validateArgCount('Firebase.DataSnapshot.exportVal', 0, 0, arguments.length);
-  return this.node_.val(true);
-};
-
-// Do not create public documentation. This is intended to make JSON serialization work but is otherwise unnecessary
-// for end-users
-DataSnapshot.prototype.toJSON = function() {
-  // Optional spacer argument is unnecessary because we're depending on recursion rather than stringifying the content
-  validateArgCount('Firebase.DataSnapshot.toJSON', 0, 1, arguments.length);
-  return this.exportVal();
-};
-
-/**
- * Returns whether the snapshot contains a non-null value.
- *
- * @return {boolean} Whether the snapshot contains a non-null value, or is empty.
- */
-DataSnapshot.prototype.exists = function() {
-  validateArgCount('Firebase.DataSnapshot.exists', 0, 0, arguments.length);
-  return !this.node_.isEmpty();
-};
+  /**
+   * Returns a DataSnapshot of the specified child node's contents.
+   *
+   * @param {!string} childPathString Path to a child.
+   * @return {!DataSnapshot} DataSnapshot for child node.
+   */
+  child(childPathString: string): DataSnapshot {
+    validateArgCount('DataSnapshot.child', 0, 1, arguments.length);
+    // Ensure the childPath is a string (can be a number)
+    childPathString = String(childPathString);
+    validatePathString('DataSnapshot.child', 1, childPathString, false);
 
-/**
- * Returns a DataSnapshot of the specified child node's contents.
- *
- * @param {!string} childPathString Path to a child.
- * @return {!DataSnapshot} DataSnapshot for child node.
- */
-DataSnapshot.prototype.child = function(childPathString) {
-  validateArgCount('Firebase.DataSnapshot.child', 0, 1, arguments.length);
-  // Ensure the childPath is a string (can be a number)
-  childPathString = String(childPathString);
-  validatePathString('Firebase.DataSnapshot.child', 1, childPathString, false);
+    const childPath = new Path(childPathString);
+    const childRef = this.ref_.child(childPath);
+    return new DataSnapshot(this.node_.getChild(childPath), childRef, PRIORITY_INDEX);
+  }
 
-  var childPath = new Path(childPathString);
-  var childRef = this.query_.child(childPath);
-  return new DataSnapshot(this.node_.getChild(childPath), childRef, PRIORITY_INDEX);
-};
+  /**
+   * Returns whether the snapshot contains a child at the specified path.
+   *
+   * @param {!string} childPathString Path to a child.
+   * @return {boolean} Whether the child exists.
+   */
+  hasChild(childPathString: string): boolean {
+    validateArgCount('DataSnapshot.hasChild', 1, 1, arguments.length);
+    validatePathString('DataSnapshot.hasChild', 1, childPathString, false);
 
-/**
- * Returns whether the snapshot contains a child at the specified path.
- *
- * @param {!string} childPathString Path to a child.
- * @return {boolean} Whether the child exists.
- */
-DataSnapshot.prototype.hasChild = function(childPathString) {
-  validateArgCount('Firebase.DataSnapshot.hasChild', 1, 1, arguments.length);
-  validatePathString('Firebase.DataSnapshot.hasChild', 1, childPathString, false);
+    const childPath = new Path(childPathString);
+    return !this.node_.getChild(childPath).isEmpty();
+  }
 
-  var childPath = new Path(childPathString);
-  return !this.node_.getChild(childPath).isEmpty();
-};
+  /**
+   * Returns the priority of the object, or null if no priority was set.
+   *
+   * @return {string|number|null} The priority.
+   */
+  getPriority(): string | number | null {
+    validateArgCount('DataSnapshot.getPriority', 0, 0, arguments.length);
 
-/**
- * Returns the priority of the object, or null if no priority was set.
- *
- * @return {string|number|null} The priority.
- */
-DataSnapshot.prototype.getPriority = function() {
-  validateArgCount('Firebase.DataSnapshot.getPriority', 0, 0, arguments.length);
+    // typecast here because we never return deferred values or internal priorities (MAX_PRIORITY)
+    return /**@type {string|number|null} */ <string | number | null>(this.node_.getPriority().val());
+  }
 
-  // typecast here because we never return deferred values or internal priorities (MAX_PRIORITY)
-  return /**@type {string|number|null} */ (this.node_.getPriority().val());
-};
+  /**
+   * Iterates through child nodes and calls the specified action for each one.
+   *
+   * @param {function(!DataSnapshot)} action Callback function to be called
+   * for each child.
+   * @return {boolean} True if forEach was canceled by action returning true for
+   * one of the child nodes.
+   */
+  forEach(action: (d: DataSnapshot) => any): boolean {
+    validateArgCount('DataSnapshot.forEach', 1, 1, arguments.length);
+    validateCallback('DataSnapshot.forEach', 1, action, false);
 
-/**
- * Iterates through child nodes and calls the specified action for each one.
- *
- * @param {function(!DataSnapshot)} action Callback function to be called
- * for each child.
- * @return {boolean} True if forEach was canceled by action returning true for
- * one of the child nodes.
- */
-DataSnapshot.prototype.forEach = function(action) {
-  validateArgCount('Firebase.DataSnapshot.forEach', 1, 1, arguments.length);
-  validateCallback('Firebase.DataSnapshot.forEach', 1, action, false);
+    if (this.node_.isLeafNode())
+      return false;
 
-  if (this.node_.isLeafNode())
-    return false;
+    const childrenNode = /**@type {ChildrenNode} */ <ChildrenNode>(this.node_);
+    // Sanitize the return value to a boolean. ChildrenNode.forEachChild has a weird return type...
+    return !!childrenNode.forEachChild(this.index_, (key, node) => {
+      return action(new DataSnapshot(node, this.ref_.child(key), PRIORITY_INDEX));
+    });
+  }
 
-  var childrenNode = /** @type {!fb.core.snap.ChildrenNode} */ (this.node_);
-  var self = this;
-  // Sanitize the return value to a boolean. ChildrenNode.forEachChild has a weird return type...
-  return !!childrenNode.forEachChild(this.index_, function(key, node) {
-    return action(new DataSnapshot(node, self.query_.child(key), PRIORITY_INDEX));
-  });
-};
+  /**
+   * Returns whether this DataSnapshot has children.
+   * @return {boolean} True if the DataSnapshot contains 1 or more child nodes.
+   */
+  hasChildren(): boolean {
+    validateArgCount('DataSnapshot.hasChildren', 0, 0, arguments.length);
 
-/**
- * Returns whether this DataSnapshot has children.
- * @return {boolean} True if the DataSnapshot contains 1 or more child nodes.
- */
-DataSnapshot.prototype.hasChildren = function() {
-  validateArgCount('Firebase.DataSnapshot.hasChildren', 0, 0, arguments.length);
+    if (this.node_.isLeafNode())
+      return false;
+    else
+      return !this.node_.isEmpty();
+  }
 
-  if (this.node_.isLeafNode())
-    return false;
-  else
-    return !this.node_.isEmpty();
-};
+  /**
+   * @return {?string} The key of the location this snapshot's data came from.
+   */
+  getKey(): string | null {
+    validateArgCount('DataSnapshot.key', 0, 0, arguments.length);
 
-/**
- * @return {?string} The key of the location this snapshot's data came from.
- */
-DataSnapshot.prototype.getKey = function() {
-  validateArgCount('Firebase.DataSnapshot.key', 0, 0, arguments.length);
+    return this.ref_.getKey();
+  }
 
-  return this.query_.getKey();
-};
-exportPropGetter(DataSnapshot.prototype, 'key', DataSnapshot.prototype.getKey);
+  get key() {
+    return this.getKey();
+  }
 
+  /**
+   * Returns the number of children for this DataSnapshot.
+   * @return {number} The number of children that this DataSnapshot contains.
+   */
+  numChildren(): number {
+    validateArgCount('DataSnapshot.numChildren', 0, 0, arguments.length);
 
-/**
- * Returns the number of children for this DataSnapshot.
- * @return {number} The number of children that this DataSnapshot contains.
- */
-DataSnapshot.prototype.numChildren = function() {
-  validateArgCount('Firebase.DataSnapshot.numChildren', 0, 0, arguments.length);
+    return this.node_.numChildren();
+  }
 
-  return this.node_.numChildren();
-};
+  /**
+   * @return {Reference} The Firebase reference for the location this snapshot's data came from.
+   */
+  getRef(): Reference {
+    validateArgCount('DataSnapshot.ref', 0, 0, arguments.length);
 
-/**
- * @return {Firebase} The Firebase reference for the location this snapshot's data came from.
- */
-DataSnapshot.prototype.getRef = function() {
-  validateArgCount('Firebase.DataSnapshot.ref', 0, 0, arguments.length);
+    return this.ref_;
+  }
 
-  return this.query_;
-};
-exportPropGetter(DataSnapshot.prototype, 'ref', DataSnapshot.prototype.getRef);
+  get ref() {
+    return this.getRef();
+  }
+}