allow to pass popper.js configuration for tooltip/popover and dropdown

js/src/tooltip/tooltip.js

@@ -56,7 +56,8 @@ const DefaultType = {
   boundary: '(string|element)',
   sanitize: 'boolean',
   sanitizeFn: '(null|function)',
-  whiteList: 'object'
+  whiteList: 'object',
+  popperConfig: '(null|object)'
 }
 
 const AttachmentMap = {
@@ -84,7 +85,8 @@ const Default = {
   boundary: 'scrollParent',
   sanitize: true,
   sanitizeFn: null,
-  whiteList: DefaultWhitelist
+  whiteList: DefaultWhitelist,
+  popperConfig: null
 }
 
 const HoverState = {
@@ -129,10 +131,6 @@ const Trigger = {
 
 class Tooltip {
   constructor(element, config) {
-    /**
-     * Check for Popper dependency
-     * Popper - https://popper.js.org
-     */
     if (typeof Popper === 'undefined') {
       throw new TypeError('Bootstrap\'s tooltips require Popper.js (https://popper.js.org)')
     }
@@ -247,7 +245,7 @@ class Tooltip {
     this._timeout = null
     this._hoverState = null
     this._activeTrigger = null
-    if (this._popper !== null) {
+    if (this._popper) {
       this._popper.destroy()
     }
 
@@ -301,27 +299,7 @@ class Tooltip {
 
       EventHandler.trigger(this.element, this.constructor.Event.INSERTED)
 
-      this._popper = new Popper(this.element, tip, {
-        placement: attachment,
-        modifiers: {
-          offset: this._getOffset(),
-          flip: {
-            behavior: this.config.fallbackPlacement
-          },
-          arrow: {
-            element: `.${this.constructor.NAME}-arrow`
-          },
-          preventOverflow: {
-            boundariesElement: this.config.boundary
-          }
-        },
-        onCreate: data => {
-          if (data.originalPlacement !== data.placement) {
-            this._handlePopperPlacementChange(data)
-          }
-        },
-        onUpdate: data => this._handlePopperPlacementChange(data)
-      })
+      this._popper = new Popper(this.element, tip, this._getPopperConfig(attachment))
 
       tip.classList.add(ClassName.SHOW)
 
@@ -482,6 +460,40 @@ class Tooltip {
 
   // Private
 
+  _getPopperConfig(attachment) {
+    const defaultBsConfig = {
+      placement: attachment,
+      modifiers: {
+        offset: this._getOffset(),
+        flip: {
+          behavior: this.config.fallbackPlacement
+        },
+        arrow: {
+          element: `.${this.constructor.NAME}-arrow`
+        },
+        preventOverflow: {
+          boundariesElement: this.config.boundary
+        }
+      },
+      onCreate: data => {
+        if (data.originalPlacement !== data.placement) {
+          this._handlePopperPlacementChange(data)
+        }
+      },
+      onUpdate: data => this._handlePopperPlacementChange(data)
+    }
+
+    let resultConfig = defaultBsConfig
+    if (this.config.popperConfig) {
+      resultConfig = {
+        ...defaultBsConfig,
+        ...this.config.popperConfig
+      }
+    }
+
+    return resultConfig
+  }
+
   _addAttachmentClass(attachment) {
     this.getTipElement().classList.add(`${CLASS_PREFIX}-${attachment}`)
   }