1 files changed, 81 insertions, 0 deletions

diff --git a/popperjs/package/lib/utils/validateModifiers.js b/popperjs/package/lib/utils/validateModifiers.js
new file mode 100644
index 0000000..5bddf51
--- /dev/null
+++ b/popperjs/package/lib/utils/validateModifiers.js
@@ -0,0 +1,81 @@
+import format from "./format.js";
+import { modifierPhases } from "../enums.js";
+var INVALID_MODIFIER_ERROR = 'Popper: modifier "%s" provided an invalid %s property, expected %s but got %s';
+var MISSING_DEPENDENCY_ERROR = 'Popper: modifier "%s" requires "%s", but "%s" modifier is not available';
+var VALID_PROPERTIES = ['name', 'enabled', 'phase', 'fn', 'effect', 'requires', 'options'];
+export default function validateModifiers(modifiers) {
+  modifiers.forEach(function (modifier) {
+    [].concat(Object.keys(modifier), VALID_PROPERTIES) // IE11-compatible replacement for `new Set(iterable)`
+    .filter(function (value, index, self) {
+      return self.indexOf(value) === index;
+    }).forEach(function (key) {
+      switch (key) {
+        case 'name':
+          if (typeof modifier.name !== 'string') {
+            console.error(format(INVALID_MODIFIER_ERROR, String(modifier.name), '"name"', '"string"', "\"" + String(modifier.name) + "\""));
+          }
+
+          break;
+
+        case 'enabled':
+          if (typeof modifier.enabled !== 'boolean') {
+            console.error(format(INVALID_MODIFIER_ERROR, modifier.name, '"enabled"', '"boolean"', "\"" + String(modifier.enabled) + "\""));
+          }
+
+          break;
+
+        case 'phase':
+          if (modifierPhases.indexOf(modifier.phase) < 0) {
+            console.error(format(INVALID_MODIFIER_ERROR, modifier.name, '"phase"', "either " + modifierPhases.join(', '), "\"" + String(modifier.phase) + "\""));
+          }
+
+          break;
+
+        case 'fn':
+          if (typeof modifier.fn !== 'function') {
+            console.error(format(INVALID_MODIFIER_ERROR, modifier.name, '"fn"', '"function"', "\"" + String(modifier.fn) + "\""));
+          }
+
+          break;
+
+        case 'effect':
+          if (modifier.effect != null && typeof modifier.effect !== 'function') {
+            console.error(format(INVALID_MODIFIER_ERROR, modifier.name, '"effect"', '"function"', "\"" + String(modifier.fn) + "\""));
+          }
+
+          break;
+
+        case 'requires':
+          if (modifier.requires != null && !Array.isArray(modifier.requires)) {
+            console.error(format(INVALID_MODIFIER_ERROR, modifier.name, '"requires"', '"array"', "\"" + String(modifier.requires) + "\""));
+          }
+
+          break;
+
+        case 'requiresIfExists':
+          if (!Array.isArray(modifier.requiresIfExists)) {
+            console.error(format(INVALID_MODIFIER_ERROR, modifier.name, '"requiresIfExists"', '"array"', "\"" + String(modifier.requiresIfExists) + "\""));
+          }
+
+          break;
+
+        case 'options':
+        case 'data':
+          break;
+
+        default:
+          console.error("PopperJS: an invalid property has been provided to the \"" + modifier.name + "\" modifier, valid properties are " + VALID_PROPERTIES.map(function (s) {
+            return "\"" + s + "\"";
+          }).join(', ') + "; but \"" + key + "\" was provided.");
+      }
+
+      modifier.requires && modifier.requires.forEach(function (requirement) {
+        if (modifiers.find(function (mod) {
+          return mod.name === requirement;
+        }) == null) {
+          console.error(format(MISSING_DEPENDENCY_ERROR, String(modifier.name), requirement, requirement));
+        }
+      });
+    });
+  });
+}
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