From 2749cfdf8fc893ce0f068a7e41045f72a3f39cbc Mon Sep 17 00:00:00 2001
From: Alex Abenoja <abenojaalex@gmail.com>
Date: Fri, 15 May 2015 00:14:49 -0600
Subject: [PATCH] [added] CustomPropTypes.singlePropFrom

Throw an error if multiple properties in the given list have a value
---
 src/utils/CustomPropTypes.js | 30 +++++++++++++++++++++++++++++-
 test/CustomPropTypesSpec.js  | 20 ++++++++++++++++++++
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/src/utils/CustomPropTypes.js b/src/utils/CustomPropTypes.js
index c56a0a4e8a..5a6ae4e0fc 100644
--- a/src/utils/CustomPropTypes.js
+++ b/src/utils/CustomPropTypes.js
@@ -22,7 +22,17 @@ let CustomPropTypes = {
    * @param componentName
    * @returns {Error|undefined}
    */
-  keyOf: createKeyOfChecker
+  keyOf: createKeyOfChecker,
+  /**
+   * Checks if only one of the listed properties is in use. An error is given
+   * if multiple have a value
+   *
+   * @param props
+   * @param propName
+   * @param componentName
+   * @returns {Error|undefined}
+   */
+  singlePropFrom: createSinglePropFromChecker
 };
 
 /**
@@ -80,4 +90,22 @@ function createKeyOfChecker(obj) {
   return createChainableTypeChecker(validate);
 }
 
+function createSinglePropFromChecker(arrOfProps) {
+  function validate(props, propName, componentName) {
+    const usedPropCount = arrOfProps
+      .map(listedProp => props[listedProp])
+      .reduce((acc, curr) => acc + (curr !== undefined ? 1 : 0), 0);
+
+    if (usedPropCount > 1) {
+      const [first, ...others] = arrOfProps;
+      const message = `${others.join(', ')} and ${first}`;
+      return new Error(
+        `Invalid prop '${propName}', only one of the following ` +
+        `may be provided: ${message}`
+      );
+    }
+  }
+  return validate;
+}
+
 export default CustomPropTypes;
diff --git a/test/CustomPropTypesSpec.js b/test/CustomPropTypesSpec.js
index 9a0b94deb2..d28137f585 100644
--- a/test/CustomPropTypesSpec.js
+++ b/test/CustomPropTypesSpec.js
@@ -47,4 +47,24 @@ describe('CustomPropTypes', function () {
       assert.isUndefined(validate('bar'));
     });
   });
+
+  describe('singlePropFrom', function () {
+    function validate(testProps) {
+      const propList = ['children', 'value'];
+
+      return CustomPropTypes.singlePropFrom(propList)(testProps, 'value', 'Component');
+    }
+
+    it('Should return undefined if only one listed prop in used', function () {
+      const testProps = {value: 5};
+
+      assert.isUndefined(validate(testProps));
+    });
+
+    it('Should return error if multiple of the listed properties have values', function () {
+      const testProps = {value: 5, children: 5};
+
+      validate(testProps).should.be.instanceOf(Error);
+    });
+  });
 });