Change constructors to connectedCallbacks

Since `constructor` can be error-prone for custom elements and keep all
the components similar, I've also changed all the constructors to
`connectedCallback` functions.

Author: koddsson

src/index.ts

@@ -130,8 +130,7 @@ if (!window.customElements.get('md-header')) {
 }
 
 class MarkdownBoldButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '**', suffix: '**', trimFirst: true})
   }
 }
@@ -142,8 +141,7 @@ if (!window.customElements.get('md-bold')) {
 }
 
 class MarkdownItalicButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '_', suffix: '_', trimFirst: true})
   }
 }
@@ -154,8 +152,7 @@ if (!window.customElements.get('md-italic')) {
 }
 
 class MarkdownQuoteButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '> ', multiline: true, surroundWithNewlines: true})
   }
 }
@@ -166,8 +163,7 @@ if (!window.customElements.get('md-quote')) {
 }
 
 class MarkdownCodeButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '`', suffix: '`', blockPrefix: '```', blockSuffix: '```'})
   }
 }
@@ -178,8 +174,7 @@ if (!window.customElements.get('md-code')) {
 }
 
 class MarkdownLinkButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '[', suffix: '](url)', replaceNext: 'url', scanFor: 'https?://'})
   }
 }
@@ -190,8 +185,7 @@ if (!window.customElements.get('md-link')) {
 }
 
 class MarkdownImageButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '![', suffix: '](url)', replaceNext: 'url', scanFor: 'https?://'})
   }
 }
@@ -202,8 +196,7 @@ if (!window.customElements.get('md-image')) {
 }
 
 class MarkdownUnorderedListButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '- ', multiline: true, unorderedList: true})
   }
 }
@@ -214,8 +207,7 @@ if (!window.customElements.get('md-unordered-list')) {
 }
 
 class MarkdownOrderedListButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '1. ', multiline: true, orderedList: true})
   }
 }
@@ -226,8 +218,7 @@ if (!window.customElements.get('md-ordered-list')) {
 }
 
 class MarkdownTaskListButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '- [ ] ', multiline: true, surroundWithNewlines: true})
   }
 }
@@ -238,8 +229,7 @@ if (!window.customElements.get('md-task-list')) {
 }
 
 class MarkdownMentionButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '@', prefixSpace: true})
   }
 }
@@ -250,8 +240,7 @@ if (!window.customElements.get('md-mention')) {
 }
 
 class MarkdownRefButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '#', prefixSpace: true})
   }
 }
@@ -262,8 +251,7 @@ if (!window.customElements.get('md-ref')) {
 }
 
 class MarkdownStrikethroughButtonElement extends MarkdownButtonElement {
-  constructor() {
-    super()
+  connectedCallback() {
     styles.set(this, {prefix: '~~', suffix: '~~', trimFirst: true})
   }
 }