Fix <Dropdown> multi-value bug

src/components/Dropdown/Dropdown.jsx

@@ -64,7 +64,10 @@ const Dropdown = ({
   const isControlled = !!customValue;
   const selectedOptions = customValue ?? selected;
   const selectedOptionsMap = useMemo(
-    () => selectedOptions.reduce((acc, option) => ({ ...acc, [option.value]: option }), {}),
+    () =>
+      Array.isArray(selectedOptions)
+        ? selectedOptions.reduce((acc, option) => ({ ...acc, [option.value]: option }), {})
+        : {},
     [selectedOptions]
   );
   const value = multi ? selectedOptions : customValue;

src/components/Dropdown/__tests__/driver.js

@@ -24,10 +24,6 @@ export default class DropdownDriver {
     this.renderResult = render(<Dropdown {...this.props} />);
   }
 
-  rerender() {
-    this.renderResult = this.renderResult.rerender();
-  }
-
   ensureRendered() {
     if (!this.renderResult) {
       this.render();
@@ -65,6 +61,10 @@ export default class DropdownDriver {
     );
   }
 
+  get singleValueText() {
+    return this.renderResult.container.querySelector("[class*='singleValue']").innerHTML;
+  }
+
   focusInput() {
     this.ensureRendered();
 
@@ -184,6 +184,10 @@ export default class DropdownDriver {
     return this.setProp("value", value);
   }
 
+  withOnChange(onChange) {
+    return this.setProp("onChange", onChange);
+  }
+
   withOnOptionSelect(onOptionSelect) {
     return this.setProp("onOptionSelect", onOptionSelect);
   }

src/components/Dropdown/__tests__/dropdown.jest.js

@@ -96,6 +96,39 @@ describe("Dropdown", () => {
     });
   });
 
+  describe.only("Controlled", () => {
+    let component;
+
+    beforeEach(() => {
+      component = new DropdownDriver().withOptions().withValue(mockOptions[0]);
+    });
+
+    it("Should display the provided value", () => {
+      component.render();
+
+      expect(component.singleValueText).toBe("Ocean");
+    });
+
+    it("Should not change value internally", () => {
+      component.selectOption(2);
+      component.render();
+
+      expect(component.singleValueText).toBe("Ocean");
+    });
+
+    it("Should change displayed value when passed a new value", () => {
+      component.withOnChange(option => {
+        component.props.value = option;
+      });
+
+      component.render();
+      component.selectOption(2);
+      component.render();
+
+      expect(component.singleValueText).toBe("Purple");
+    });
+  });
+
   describe("multi", () => {
     let component;
 
@@ -125,44 +158,44 @@ describe("Dropdown", () => {
       component.selectOption(0);
 
       component.clearOptions();
-      component.rerender();
+      component.render();
 
       expect(component.chips.values).toEqual([]);
     });
 
     describe("Controlled", () => {
-      let options;
+      let value;
 
       beforeEach(() => {
-        options = [component.options[0], component.options[2]];
-        component.withValue(options);
+        value = [component.options[0], component.options[2]];
+        component.withValue(value);
       });
 
       it("Should support selecting multiple options", () => {
-        component.withOnOptionSelect(option => options.push(option));
+        component.withOnOptionSelect(option => value.push(option));
 
         component.selectOption(3);
-        component.rerender();
+        component.render();
 
         expect(component.chips.values).toEqual(["ocean", "purple", "red"]);
       });
 
       it("Should support removing options", () => {
-        component.withOnOptionRemove(() => options.pop());
+        component.withOnOptionRemove(() => value.pop());
 
         component.removeOption(2);
-        component.rerender();
+        component.render();
 
         expect(component.chips.values).toEqual(["ocean"]);
       });
 
       it("Should support clearing options", () => {
         component.withOnClear(() => {
-          options.length = 0;
+          value.length = 0;
         });
 
         component.clearOptions();
-        component.rerender();
+        component.render();
 
         expect(component.chips.values).toEqual([]);
       });