From cf2b896e4e1491397aa1a41e8592c1de0ba40353 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Sun, 7 Jul 2019 12:42:13 +0800
Subject: [PATCH 01/17] Add dataURLs support

---
 index.js | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 test.js  | 19 +++++++++++++++++++
 2 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index ac386a0..39ce543 100644
--- a/index.js
+++ b/index.js
@@ -6,6 +6,50 @@ const testParameter = (name, filters) => {
 	return filters.some(filter => filter instanceof RegExp ? filter.test(name) : filter === name);
 };
 
+// from https://github.com/killmenot/valid-data-url/blob/8d56cab866469a4608001f0e8c5d73f65789ba13/index.js#L24
+const dataURLRegex = /^data:([a-z]+\/[a-z0-9-+.]+(;[a-z0-9-.!#$%*+.{}|~`]+=[a-z0-9-.!#$%*+.{}|~`]+)*)?(;base64)?,([a-z0-9!$&',()*+;=\-._~:@\/?%\s]*?)$/i;
+
+const isValidDataURL = urlString => {
+  return dataURLRegex.test(urlString)
+}
+
+const parseDataURL = urlString => {
+	if (!isValidDataURL(urlString)) {
+		throw new Error(`Invalid URL: ${urlString}`);
+	}
+
+  const parts = urlString.trim().match(dataURLRegex);
+  const parsed = {};
+
+  if (parts[1]) {
+		const mimeType = parts[1].toLowerCase();
+    const [contentType, ...attributes] = mimeType.split(';');
+		// TODO: use `Object.fromEntries`
+		// Object.assign(parsed, Object.fromEntries(attributes.map(attribute => attribute.split('='))))
+		attributes.reduce((parsed, attribute) => {
+			const [key, value] = attribute.split('=')
+			parsed[key] = value
+			return parsed;
+		}, parsed);
+
+		parsed.mimeType = mimeType;
+    parsed.contentType = contentType;
+  }
+
+  parsed.base64 = !!parts[parts.length - 2];
+  parsed.body = parts[parts.length - 1] || '';
+
+  return parsed;
+};
+
+const normalizeDataURL = urlString => {
+	const data = parseDataURL(urlString);
+
+	const body = data.base64 ? data.body.trim() : data.body
+
+	return `data:${data.mimeType}${data.base64 ? ';base64' : ''},${body}`
+}
+
 const normalizeUrl = (urlString, options) => {
 	options = {
 		defaultProtocol: 'http:',
@@ -41,7 +85,7 @@ const normalizeUrl = (urlString, options) => {
 	const isRelativeUrl = !hasRelativeProtocol && /^\.*\//.test(urlString);
 
 	// Prepend protocol
-	if (!isRelativeUrl) {
+	if (!isRelativeUrl && !/^data?:/i.test(urlString)) {
 		urlString = urlString.replace(/^(?!(?:\w+:)?\/\/)|^\/\//, options.defaultProtocol);
 	}
 
@@ -152,6 +196,11 @@ const normalizeUrl = (urlString, options) => {
 		urlString = urlString.replace(/^(?:https?:)?\/\//, '');
 	}
 
+	if (urlObj.protocol === 'data:') {
+		const url = normalizeDataURL(`${urlObj.protocol}${urlObj.pathname}`)
+		return `${url}${urlObj.search}${urlObj.hash}`
+	}
+
 	return urlString;
 };
 
diff --git a/test.js b/test.js
index 5fbc8b4..8e01565 100644
--- a/test.js
+++ b/test.js
@@ -204,3 +204,22 @@ test('remove duplicate pathname slashes', t => {
 	t.is(normalizeUrl('http://sindresorhus.com:5000//foo'), 'http://sindresorhus.com:5000/foo');
 	t.is(normalizeUrl('http://sindresorhus.com//foo'), 'http://sindresorhus.com/foo');
 });
+
+test('DataURLs', t => {
+	t.throws(() => {
+		normalizeUrl('data:text/plain;charset=UTF-8;,foo');
+	}, 'Invalid URL: data:text/plain;charset=UTF-8;,foo');
+	// Lowercase the mimeType
+	t.is(normalizeUrl('data:TEXT/plain;charset=UTF-8,foo'), 'data:text/plain;charset=utf-8,foo');
+	// Remove spaces after the comma when it's base64
+	t.is(normalizeUrl('data:image/gif;base64, R0lGODlhAQABAAAAACw= ?foo=bar'), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar');
+	// Keep spaces when it's not base64
+	t.is(normalizeUrl('data:text/plain;charset=utf-8, foo ?foo=bar'), 'data:text/plain;charset=utf-8, foo?foo=bar');
+	// with query and hash
+	t.is(normalizeUrl('data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar#baz'), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar#baz');
+	// removeQueryParameters & stripHash
+	t.is(normalizeUrl('data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar&utm_medium=test#baz', {
+		removeQueryParameters: [/^utm_\w+/i, 'ref'],
+		stripHash: true
+	}), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar');
+})

From b9d9b99a66678099453ffc659c6e2372fe7ed81d Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Sun, 7 Jul 2019 12:53:38 +0800
Subject: [PATCH 02/17] style: fix code style

---
 index.js | 39 ++++++++++++++++++++-------------------
 test.js  |  6 +++---
 2 files changed, 23 insertions(+), 22 deletions(-)

diff --git a/index.js b/index.js
index 39ce543..5882826 100644
--- a/index.js
+++ b/index.js
@@ -6,49 +6,50 @@ const testParameter = (name, filters) => {
 	return filters.some(filter => filter instanceof RegExp ? filter.test(name) : filter === name);
 };
 
-// from https://github.com/killmenot/valid-data-url/blob/8d56cab866469a4608001f0e8c5d73f65789ba13/index.js#L24
+// From https://github.com/killmenot/valid-data-url/blob/8d56cab866469a4608001f0e8c5d73f65789ba13/index.js#L24
+// eslint-disable-next-line no-useless-escape
 const dataURLRegex = /^data:([a-z]+\/[a-z0-9-+.]+(;[a-z0-9-.!#$%*+.{}|~`]+=[a-z0-9-.!#$%*+.{}|~`]+)*)?(;base64)?,([a-z0-9!$&',()*+;=\-._~:@\/?%\s]*?)$/i;
 
 const isValidDataURL = urlString => {
-  return dataURLRegex.test(urlString)
-}
+	return dataURLRegex.test(urlString);
+};
 
 const parseDataURL = urlString => {
 	if (!isValidDataURL(urlString)) {
 		throw new Error(`Invalid URL: ${urlString}`);
 	}
 
-  const parts = urlString.trim().match(dataURLRegex);
-  const parsed = {};
+	const parts = urlString.trim().match(dataURLRegex);
+	const parsed = {};
 
-  if (parts[1]) {
+	if (parts[1]) {
 		const mimeType = parts[1].toLowerCase();
-    const [contentType, ...attributes] = mimeType.split(';');
+		const [contentType, ...attributes] = mimeType.split(';');
 		// TODO: use `Object.fromEntries`
 		// Object.assign(parsed, Object.fromEntries(attributes.map(attribute => attribute.split('='))))
 		attributes.reduce((parsed, attribute) => {
-			const [key, value] = attribute.split('=')
-			parsed[key] = value
+			const [key, value] = attribute.split('=');
+			parsed[key] = value;
 			return parsed;
 		}, parsed);
 
 		parsed.mimeType = mimeType;
-    parsed.contentType = contentType;
-  }
+		parsed.contentType = contentType;
+	}
 
-  parsed.base64 = !!parts[parts.length - 2];
-  parsed.body = parts[parts.length - 1] || '';
+	parsed.base64 = Boolean(parts[parts.length - 2]);
+	parsed.body = parts[parts.length - 1] || '';
 
-  return parsed;
+	return parsed;
 };
 
 const normalizeDataURL = urlString => {
 	const data = parseDataURL(urlString);
 
-	const body = data.base64 ? data.body.trim() : data.body
+	const body = data.base64 ? data.body.trim() : data.body;
 
-	return `data:${data.mimeType}${data.base64 ? ';base64' : ''},${body}`
-}
+	return `data:${data.mimeType}${data.base64 ? ';base64' : ''},${body}`;
+};
 
 const normalizeUrl = (urlString, options) => {
 	options = {
@@ -197,8 +198,8 @@ const normalizeUrl = (urlString, options) => {
 	}
 
 	if (urlObj.protocol === 'data:') {
-		const url = normalizeDataURL(`${urlObj.protocol}${urlObj.pathname}`)
-		return `${url}${urlObj.search}${urlObj.hash}`
+		const url = normalizeDataURL(`${urlObj.protocol}${urlObj.pathname}`);
+		return `${url}${urlObj.search}${urlObj.hash}`;
 	}
 
 	return urlString;
diff --git a/test.js b/test.js
index 8e01565..f8efe97 100644
--- a/test.js
+++ b/test.js
@@ -215,11 +215,11 @@ test('DataURLs', t => {
 	t.is(normalizeUrl('data:image/gif;base64, R0lGODlhAQABAAAAACw= ?foo=bar'), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar');
 	// Keep spaces when it's not base64
 	t.is(normalizeUrl('data:text/plain;charset=utf-8, foo ?foo=bar'), 'data:text/plain;charset=utf-8, foo?foo=bar');
-	// with query and hash
+	// DataURL with query and hash
 	t.is(normalizeUrl('data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar#baz'), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar#baz');
-	// removeQueryParameters & stripHash
+	// Options: removeQueryParameters & stripHash
 	t.is(normalizeUrl('data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar&utm_medium=test#baz', {
 		removeQueryParameters: [/^utm_\w+/i, 'ref'],
 		stripHash: true
 	}), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar');
-})
+});

From bcd7157f1e2ba281fb1bc6db7aa9ca3ddce228e8 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Sun, 7 Jul 2019 13:03:10 +0800
Subject: [PATCH 03/17] more options test

---
 index.js | 11 ++++++-----
 test.js  | 16 ++++++++++++----
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/index.js b/index.js
index 5882826..04574a3 100644
--- a/index.js
+++ b/index.js
@@ -175,6 +175,12 @@ const normalizeUrl = (urlString, options) => {
 		urlObj.searchParams.sort();
 	}
 
+	// DataUrls
+	if (urlObj.protocol === 'data:') {
+		const url = normalizeDataURL(`${urlObj.protocol}${urlObj.pathname}`);
+		return `${url}${urlObj.search}${urlObj.hash}`;
+	}
+
 	if (options.removeTrailingSlash) {
 		urlObj.pathname = urlObj.pathname.replace(/\/$/, '');
 	}
@@ -197,11 +203,6 @@ const normalizeUrl = (urlString, options) => {
 		urlString = urlString.replace(/^(?:https?:)?\/\//, '');
 	}
 
-	if (urlObj.protocol === 'data:') {
-		const url = normalizeDataURL(`${urlObj.protocol}${urlObj.pathname}`);
-		return `${url}${urlObj.search}${urlObj.hash}`;
-	}
-
 	return urlString;
 };
 
diff --git a/test.js b/test.js
index f8efe97..6e09854 100644
--- a/test.js
+++ b/test.js
@@ -217,9 +217,17 @@ test('DataURLs', t => {
 	t.is(normalizeUrl('data:text/plain;charset=utf-8, foo ?foo=bar'), 'data:text/plain;charset=utf-8, foo?foo=bar');
 	// DataURL with query and hash
 	t.is(normalizeUrl('data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar#baz'), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar#baz');
-	// Options: removeQueryParameters & stripHash
-	t.is(normalizeUrl('data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar&utm_medium=test#baz', {
+	// Options
+	t.is(normalizeUrl('data:text/plain;charset=utf-8,www.foo/index.html?foo=bar&a=a&utm_medium=test#baz', {
+		defaultProtocol: 'http:',
+		normalizeProtocol: true,
+		forceHttp: true,
+		stripHash: true,
+		stripWWW: true,
+		stripProtocol: true,
 		removeQueryParameters: [/^utm_\w+/i, 'ref'],
-		stripHash: true
-	}), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar');
+		sortQueryParameters: true,
+		removeTrailingSlash: true,
+		removeDirectoryIndex: true
+	}), 'data:text/plain;charset=utf-8,www.foo/index.html?a=a&foo=bar');
 });

From 2585bb2356d5235aa3576a60eb816efe516cf44a Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Sun, 7 Jul 2019 13:12:11 +0800
Subject: [PATCH 04/17] test: cover empty mimeType

---
 index.js | 3 ++-
 test.js  | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 04574a3..3eae79c 100644
--- a/index.js
+++ b/index.js
@@ -47,8 +47,9 @@ const normalizeDataURL = urlString => {
 	const data = parseDataURL(urlString);
 
 	const body = data.base64 ? data.body.trim() : data.body;
+	const {mimeType = ''} = data
 
-	return `data:${data.mimeType}${data.base64 ? ';base64' : ''},${body}`;
+	return `data:${mimeType}${data.base64 ? ';base64' : ''},${body}`;
 };
 
 const normalizeUrl = (urlString, options) => {
diff --git a/test.js b/test.js
index 6e09854..c90f1c9 100644
--- a/test.js
+++ b/test.js
@@ -209,6 +209,8 @@ test('DataURLs', t => {
 	t.throws(() => {
 		normalizeUrl('data:text/plain;charset=UTF-8;,foo');
 	}, 'Invalid URL: data:text/plain;charset=UTF-8;,foo');
+	// Empty mimeType
+	t.is(normalizeUrl('data:,'), 'data:,');
 	// Lowercase the mimeType
 	t.is(normalizeUrl('data:TEXT/plain;charset=UTF-8,foo'), 'data:text/plain;charset=utf-8,foo');
 	// Remove spaces after the comma when it's base64

From b637a57f1136df3cccb1a513b6e36ab9bd3784f3 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Sun, 7 Jul 2019 13:14:27 +0800
Subject: [PATCH 05/17] code style

---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index 3eae79c..3bdcf2f 100644
--- a/index.js
+++ b/index.js
@@ -47,7 +47,7 @@ const normalizeDataURL = urlString => {
 	const data = parseDataURL(urlString);
 
 	const body = data.base64 ? data.body.trim() : data.body;
-	const {mimeType = ''} = data
+	const {mimeType = ''} = data;
 
 	return `data:${mimeType}${data.base64 ? ';base64' : ''},${body}`;
 };

From c5f933346e6be13be2eaf33fae80c9b3ab36e0ce Mon Sep 17 00:00:00 2001
From: Sindre Sorhus <sindresorhus@gmail.com>
Date: Tue, 17 Sep 2019 12:59:23 +0700
Subject: [PATCH 06/17] Update test.js

---
 test.js | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/test.js b/test.js
index c90f1c9..859867f 100644
--- a/test.js
+++ b/test.js
@@ -205,21 +205,27 @@ test('remove duplicate pathname slashes', t => {
 	t.is(normalizeUrl('http://sindresorhus.com//foo'), 'http://sindresorhus.com/foo');
 });
 
-test('DataURLs', t => {
+test('data URL', t => {
 	t.throws(() => {
 		normalizeUrl('data:text/plain;charset=UTF-8;,foo');
 	}, 'Invalid URL: data:text/plain;charset=UTF-8;,foo');
-	// Empty mimeType
+
+	// Empty MIME type.
 	t.is(normalizeUrl('data:,'), 'data:,');
-	// Lowercase the mimeType
+
+	// Lowercase the MIME type.
 	t.is(normalizeUrl('data:TEXT/plain;charset=UTF-8,foo'), 'data:text/plain;charset=utf-8,foo');
-	// Remove spaces after the comma when it's base64
+
+	// Remove spaces after the comma when it's base64.
 	t.is(normalizeUrl('data:image/gif;base64, R0lGODlhAQABAAAAACw= ?foo=bar'), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar');
-	// Keep spaces when it's not base64
+
+	// Keep spaces when it's not base64.
 	t.is(normalizeUrl('data:text/plain;charset=utf-8, foo ?foo=bar'), 'data:text/plain;charset=utf-8, foo?foo=bar');
-	// DataURL with query and hash
+
+	// Data URL with query and hash.
 	t.is(normalizeUrl('data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar#baz'), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar#baz');
-	// Options
+
+	// Options.
 	t.is(normalizeUrl('data:text/plain;charset=utf-8,www.foo/index.html?foo=bar&a=a&utm_medium=test#baz', {
 		defaultProtocol: 'http:',
 		normalizeProtocol: true,

From 4af7cc426030fd1bc559e66d4e334ab954f48db7 Mon Sep 17 00:00:00 2001
From: Sindre Sorhus <sindresorhus@gmail.com>
Date: Tue, 17 Sep 2019 13:01:07 +0700
Subject: [PATCH 07/17] Update index.js

---
 index.js | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/index.js b/index.js
index 3bdcf2f..d4b896a 100644
--- a/index.js
+++ b/index.js
@@ -10,9 +10,7 @@ const testParameter = (name, filters) => {
 // eslint-disable-next-line no-useless-escape
 const dataURLRegex = /^data:([a-z]+\/[a-z0-9-+.]+(;[a-z0-9-.!#$%*+.{}|~`]+=[a-z0-9-.!#$%*+.{}|~`]+)*)?(;base64)?,([a-z0-9!$&',()*+;=\-._~:@\/?%\s]*?)$/i;
 
-const isValidDataURL = urlString => {
-	return dataURLRegex.test(urlString);
-};
+const isValidDataURL = urlString => dataURLRegex.test(urlString);
 
 const parseDataURL = urlString => {
 	if (!isValidDataURL(urlString)) {
@@ -25,7 +23,7 @@ const parseDataURL = urlString => {
 	if (parts[1]) {
 		const mimeType = parts[1].toLowerCase();
 		const [contentType, ...attributes] = mimeType.split(';');
-		// TODO: use `Object.fromEntries`
+		// TODO: Use `Object.fromEntries` when targeting Node.js 10
 		// Object.assign(parsed, Object.fromEntries(attributes.map(attribute => attribute.split('='))))
 		attributes.reduce((parsed, attribute) => {
 			const [key, value] = attribute.split('=');
@@ -45,10 +43,8 @@ const parseDataURL = urlString => {
 
 const normalizeDataURL = urlString => {
 	const data = parseDataURL(urlString);
-
 	const body = data.base64 ? data.body.trim() : data.body;
 	const {mimeType = ''} = data;
-
 	return `data:${mimeType}${data.base64 ? ';base64' : ''},${body}`;
 };
 

From 128d9552e768fb9359b7d41dbb5200f64b4d7afa Mon Sep 17 00:00:00 2001
From: Sindre Sorhus <sindresorhus@gmail.com>
Date: Tue, 17 Sep 2019 13:01:48 +0700
Subject: [PATCH 08/17] Update index.js

---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index d4b896a..f512467 100644
--- a/index.js
+++ b/index.js
@@ -172,7 +172,7 @@ const normalizeUrl = (urlString, options) => {
 		urlObj.searchParams.sort();
 	}
 
-	// DataUrls
+	// Data URL
 	if (urlObj.protocol === 'data:') {
 		const url = normalizeDataURL(`${urlObj.protocol}${urlObj.pathname}`);
 		return `${url}${urlObj.search}${urlObj.hash}`;

From 62ed83dadf2ade08a71a879b4531f6345cc43c55 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Wed, 18 Sep 2019 09:00:45 +0800
Subject: [PATCH 09/17] fix data protocol regexp

---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index f512467..35c2285 100644
--- a/index.js
+++ b/index.js
@@ -83,7 +83,7 @@ const normalizeUrl = (urlString, options) => {
 	const isRelativeUrl = !hasRelativeProtocol && /^\.*\//.test(urlString);
 
 	// Prepend protocol
-	if (!isRelativeUrl && !/^data?:/i.test(urlString)) {
+	if (!isRelativeUrl && !/^data:/i.test(urlString)) {
 		urlString = urlString.replace(/^(?!(?:\w+:)?\/\/)|^\/\//, options.defaultProtocol);
 	}
 

From f4bcdb6abf80808df09a6d426b8f0f9d5c580f58 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Wed, 18 Sep 2019 09:06:27 +0800
Subject: [PATCH 10/17] Fix eslint error

---
 index.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index 35c2285..4441090 100644
--- a/index.js
+++ b/index.js
@@ -6,9 +6,9 @@ const testParameter = (name, filters) => {
 	return filters.some(filter => filter instanceof RegExp ? filter.test(name) : filter === name);
 };
 
-// From https://github.com/killmenot/valid-data-url/blob/8d56cab866469a4608001f0e8c5d73f65789ba13/index.js#L24
-// eslint-disable-next-line no-useless-escape
-const dataURLRegex = /^data:([a-z]+\/[a-z0-9-+.]+(;[a-z0-9-.!#$%*+.{}|~`]+=[a-z0-9-.!#$%*+.{}|~`]+)*)?(;base64)?,([a-z0-9!$&',()*+;=\-._~:@\/?%\s]*?)$/i;
+// Based on valid-data-url
+// https://github.com/killmenot/valid-data-url/blob/8d56cab866469a4608001f0e8c5d73f65789ba13/index.js#L24
+const dataURLRegex = /^data:([a-z]+\/[a-z0-9-+.]+(;[a-z0-9-.!#$%*+.{}|~`]+=[a-z0-9-.!#$%*+.{}|~`]+)*)?(;base64)?,([a-z0-9!$&',()*+;=\-._~:@/?%\s]*?)$/i;
 
 const isValidDataURL = urlString => dataURLRegex.test(urlString);
 

From 6ecd048e63d21909aac65e148870e374e13dec99 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Wed, 18 Sep 2019 09:21:44 +0800
Subject: [PATCH 11/17] Use `for...of` instead of `reduce`

---
 index.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index 4441090..ddb6014 100644
--- a/index.js
+++ b/index.js
@@ -25,11 +25,10 @@ const parseDataURL = urlString => {
 		const [contentType, ...attributes] = mimeType.split(';');
 		// TODO: Use `Object.fromEntries` when targeting Node.js 10
 		// Object.assign(parsed, Object.fromEntries(attributes.map(attribute => attribute.split('='))))
-		attributes.reduce((parsed, attribute) => {
+		for (const attribute of attributes) {
 			const [key, value] = attribute.split('=');
 			parsed[key] = value;
-			return parsed;
-		}, parsed);
+		}
 
 		parsed.mimeType = mimeType;
 		parsed.contentType = contentType;

From ea704575c58d8b39dff421aca7501d7d4a502377 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Wed, 18 Sep 2019 10:56:05 +0800
Subject: [PATCH 12/17] Refactor normalizeDataURL

---
 index.js | 61 +++++++++++++++++++++++++++++---------------------------
 test.js  | 16 +++++++++++----
 2 files changed, 44 insertions(+), 33 deletions(-)

diff --git a/index.js b/index.js
index ddb6014..e769356 100644
--- a/index.js
+++ b/index.js
@@ -6,45 +6,48 @@ const testParameter = (name, filters) => {
 	return filters.some(filter => filter instanceof RegExp ? filter.test(name) : filter === name);
 };
 
-// Based on valid-data-url
-// https://github.com/killmenot/valid-data-url/blob/8d56cab866469a4608001f0e8c5d73f65789ba13/index.js#L24
-const dataURLRegex = /^data:([a-z]+\/[a-z0-9-+.]+(;[a-z0-9-.!#$%*+.{}|~`]+=[a-z0-9-.!#$%*+.{}|~`]+)*)?(;base64)?,([a-z0-9!$&',()*+;=\-._~:@/?%\s]*?)$/i;
-
-const isValidDataURL = urlString => dataURLRegex.test(urlString);
+const normalizeDataURL = urlString => {
+	const parts = urlString.trim().match(/^data:(.*?),(.*)$/);
 
-const parseDataURL = urlString => {
-	if (!isValidDataURL(urlString)) {
+	if (!parts) {
 		throw new Error(`Invalid URL: ${urlString}`);
 	}
 
-	const parts = urlString.trim().match(dataURLRegex);
-	const parsed = {};
+	const mediaType = parts[1].split(';');
+	const body = parts[2];
 
-	if (parts[1]) {
-		const mimeType = parts[1].toLowerCase();
-		const [contentType, ...attributes] = mimeType.split(';');
-		// TODO: Use `Object.fromEntries` when targeting Node.js 10
-		// Object.assign(parsed, Object.fromEntries(attributes.map(attribute => attribute.split('='))))
-		for (const attribute of attributes) {
-			const [key, value] = attribute.split('=');
-			parsed[key] = value;
-		}
+	let base64 = false;
 
-		parsed.mimeType = mimeType;
-		parsed.contentType = contentType;
+	if (mediaType[mediaType.length - 1] === 'base64') {
+		mediaType.pop();
+		base64 = true;
 	}
 
-	parsed.base64 = Boolean(parts[parts.length - 2]);
-	parsed.body = parts[parts.length - 1] || '';
+	// Lowercase MIME type
+	const mimeType = (mediaType.shift() || '').toLowerCase();
+	const attributes = mediaType
+		.filter(Boolean)
+		.map(attribute => {
+			let [key, value] = attribute.split('=').map(string => string.trim());
 
-	return parsed;
-};
+			// Lowercase `charset`
+			if (key === 'charset') {
+				value = value.toLowerCase();
+			}
 
-const normalizeDataURL = urlString => {
-	const data = parseDataURL(urlString);
-	const body = data.base64 ? data.body.trim() : data.body;
-	const {mimeType = ''} = data;
-	return `data:${mimeType}${data.base64 ? ';base64' : ''},${body}`;
+			return `${key}=${value}`;
+		});
+
+	const normalizedMediaType = [
+		...attributes,
+		base64 ? 'base64' : ''
+	].filter(Boolean);
+
+	if (normalizedMediaType.length !== 0 || mimeType) {
+		normalizedMediaType.unshift(mimeType);
+	}
+
+	return `data:${normalizedMediaType.join(';')},${base64 ? body.trim() : body}`;
 };
 
 const normalizeUrl = (urlString, options) => {
diff --git a/test.js b/test.js
index 859867f..b65347f 100644
--- a/test.js
+++ b/test.js
@@ -206,15 +206,23 @@ test('remove duplicate pathname slashes', t => {
 });
 
 test('data URL', t => {
-	t.throws(() => {
-		normalizeUrl('data:text/plain;charset=UTF-8;,foo');
-	}, 'Invalid URL: data:text/plain;charset=UTF-8;,foo');
+	// Invalid URL.
+	t.throws(() => normalizeUrl('data:'), 'Invalid URL: data:');
+
+	// Normalize away trailing semicolon.
+	t.is(normalizeUrl('data:text/plain;charset=UTF-8;,foo'), 'data:text/plain;charset=utf-8,foo');
 
 	// Empty MIME type.
 	t.is(normalizeUrl('data:,'), 'data:,');
 
+	// Empty MIME type with charset.
+	t.is(normalizeUrl('data:;charset=utf-8,foo'), 'data:;charset=utf-8,foo');
+
 	// Lowercase the MIME type.
-	t.is(normalizeUrl('data:TEXT/plain;charset=UTF-8,foo'), 'data:text/plain;charset=utf-8,foo');
+	t.is(normalizeUrl('data:TEXT/plain,foo'), 'data:text/plain,foo');
+
+	// Lowercase the charset.
+	t.is(normalizeUrl('data:text/plain;charset=UTF-8,foo'), 'data:text/plain;charset=utf-8,foo');
 
 	// Remove spaces after the comma when it's base64.
 	t.is(normalizeUrl('data:image/gif;base64, R0lGODlhAQABAAAAACw= ?foo=bar'), 'data:image/gif;base64,R0lGODlhAQABAAAAACw=?foo=bar');

From a795c236734546e5202c5257fd228005e3eb4f78 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Wed, 18 Sep 2019 11:34:10 +0800
Subject: [PATCH 13/17] remove unnecessary filter

---
 index.js | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index e769356..d14d3fa 100644
--- a/index.js
+++ b/index.js
@@ -39,9 +39,12 @@ const normalizeDataURL = urlString => {
 		});
 
 	const normalizedMediaType = [
-		...attributes,
-		base64 ? 'base64' : ''
-	].filter(Boolean);
+		...attributes
+	];
+
+	if (base64) {
+		normalizedMediaType.push('base64');
+	}
 
 	if (normalizedMediaType.length !== 0 || mimeType) {
 		normalizedMediaType.unshift(mimeType);

From 36aafd7df079592f2e6992d18d4d9d19f1d3a277 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Wed, 18 Sep 2019 11:35:10 +0800
Subject: [PATCH 14/17] Handle possible empty attribute

---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index d14d3fa..20ab9de 100644
--- a/index.js
+++ b/index.js
@@ -28,7 +28,7 @@ const normalizeDataURL = urlString => {
 	const attributes = mediaType
 		.filter(Boolean)
 		.map(attribute => {
-			let [key, value] = attribute.split('=').map(string => string.trim());
+			let [key, value = ''] = attribute.split('=').map(string => string.trim());
 
 			// Lowercase `charset`
 			if (key === 'charset') {

From e7fc28fd2a73534c74254d2de6ddc2441fbd1937 Mon Sep 17 00:00:00 2001
From: fisker <lionkay@gmail.com>
Date: Wed, 18 Sep 2019 14:08:39 +0800
Subject: [PATCH 15/17] Add `data URLs` info

---
 index.d.ts | 2 +-
 readme.md  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/index.d.ts b/index.d.ts
index 6257bf1..3a4e851 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -192,7 +192,7 @@ declare const normalizeUrl: {
 	/**
 	[Normalize](https://en.wikipedia.org/wiki/URL_normalization) a URL.
 
-	@param url - URL to normalize.
+	@param url - URL(including data URLs) to normalize.
 
 	@example
 	```
diff --git a/readme.md b/readme.md
index 4d9e5eb..5ff7886 100644
--- a/readme.md
+++ b/readme.md
@@ -33,7 +33,7 @@ normalizeUrl('HTTP://xn--xample-hva.com:80/?b=bar&a=foo');
 
 Type: `string`
 
-URL to normalize.
+URL(including data URLs) to normalize.
 
 #### options
 

From 624831836ee0c4c40d8a732e38d96ccca034183d Mon Sep 17 00:00:00 2001
From: Sindre Sorhus <sindresorhus@gmail.com>
Date: Fri, 20 Sep 2019 15:35:29 +0700
Subject: [PATCH 16/17] Update readme.md

---
 readme.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/readme.md b/readme.md
index 5ff7886..a851fdd 100644
--- a/readme.md
+++ b/readme.md
@@ -33,7 +33,7 @@ normalizeUrl('HTTP://xn--xample-hva.com:80/?b=bar&a=foo');
 
 Type: `string`
 
-URL(including data URLs) to normalize.
+URL to normalize, including [data URL](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs).
 
 #### options
 

From 53c2f0d859422ad6f3a20836a8640c7aa9c5f299 Mon Sep 17 00:00:00 2001
From: Sindre Sorhus <sindresorhus@gmail.com>
Date: Fri, 20 Sep 2019 15:36:15 +0700
Subject: [PATCH 17/17] Update index.d.ts

---
 index.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.d.ts b/index.d.ts
index 3a4e851..7e332f2 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -192,7 +192,7 @@ declare const normalizeUrl: {
 	/**
 	[Normalize](https://en.wikipedia.org/wiki/URL_normalization) a URL.
 
-	@param url - URL(including data URLs) to normalize.
+	@param url - URL to normalize, including [data URL](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs).
 
 	@example
 	```