From 5cdfff4a47f0e8a7072777aab5c7d81661131040 Mon Sep 17 00:00:00 2001 From: Jonas Jenwald Date: Thu, 13 Feb 2020 17:45:38 +0100 Subject: [PATCH] Re-factor how `Metadata` class instances store its data internally Please note that these changes do *not* affect the *public* interface of the `Metadata` class, but only touches internal structures.[1] These changes were prompted by looking at the `getAll` method, which simply returns the "private" metadata object to the consumer. This seems wrong conceptually, since it allows way too easy/accidental changes to the internal parsed metadata. As part of fixing this, the internal metadata was changed to use a `Map` rather than a plain Object. --- [1] Basically, we shouldn't need to worry about someone depending on internal implementation details. --- src/display/metadata.js | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/src/display/metadata.js b/src/display/metadata.js index 39ec932de..edd1f5935 100644 --- a/src/display/metadata.js +++ b/src/display/metadata.js @@ -27,7 +27,7 @@ class Metadata { const parser = new SimpleXMLParser(); const xmlDocument = parser.parseFromString(data); - this._metadata = Object.create(null); + this._metadataMap = new Map(); if (xmlDocument) { this._parse(xmlDocument); @@ -107,23 +107,26 @@ class Metadata { const entry = desc.childNodes[j]; const name = entry.nodeName.toLowerCase(); - this._metadata[name] = entry.textContent.trim(); + this._metadataMap.set(name, entry.textContent.trim()); } } } } get(name) { - const data = this._metadata[name]; - return typeof data !== "undefined" ? data : null; + return this._metadataMap.has(name) ? this._metadataMap.get(name) : null; } getAll() { - return this._metadata; + const obj = Object.create(null); + for (const [key, value] of this._metadataMap) { + obj[key] = value; + } + return obj; } has(name) { - return typeof this._metadata[name] !== "undefined"; + return this._metadataMap.has(name); } }