[sc-160947] Switch to partial URL encoding. (#72)

Author: kinyoklion

src/__tests__/context-test.js

@@ -77,6 +77,11 @@ describe('when determining canonical keys', () => {
     [{ kind: 'multi', user: { key: 'usertest' } }, 'user:usertest'],
     [{ kind: 'multi', user: { key: 'usertest' }, org: { key: 'orgtest' } }, 'org:orgtest:user:usertest'],
     [{ kind: 'multi', user: { key: 'user:test' }, org: { key: 'org:test' } }, 'org:org%3Atest:user:user%3Atest'],
+    [{ kind: 'multi', user: { key: 'user%test' }, org: { key: 'org%test' } }, 'org:org%25test:user:user%25test'],
+    [
+      { kind: 'multi', user: { key: 'user%:test' }, org: { key: 'org%:test' } },
+      'org:org%25%3Atest:user:user%25%3Atest',
+    ],
   ])('produces a canonical key for valid  contexts', (context, canonicalKey) => {
     expect(getCanonicalKey(context)).toEqual(canonicalKey);
   });

src/context.js

@@ -57,17 +57,33 @@ function getContextKinds(context) {
   return [];
 }
 
+/**
+ * The partial URL encoding is needed because : is a valid character in context keys.
+ *
+ * Partial encoding is the replacement of all colon (:) characters with the URL
+ * encoded equivalent (%3A) and all percent (%) characters with the URL encoded
+ * equivalent (%25).
+ * @param {string} key The key to encode.
+ * @returns {string} Partially URL encoded key.
+ */
+function encodeKey(key) {
+  if (key.includes('%') || key.includes(':')) {
+    return key.replace(/%/g, '%25').replace(/:/g, '%3A');
+  }
+  return key;
+}
+
 function getCanonicalKey(context) {
   if (context) {
     if ((context.kind === undefined || context.kind === null || context.kind === 'user') && context.key) {
       return context.key;
     } else if (context.kind !== 'multi' && context.key) {
-      return `${context.kind}:${encodeURIComponent(context.key)}`;
+      return `${context.kind}:${encodeKey(context.key)}`;
     } else if (context.kind === 'multi') {
       return Object.keys(context)
         .sort()
         .filter(key => key !== 'kind')
-        .map(key => `${key}:${encodeURIComponent(context[key].key)}`)
+        .map(key => `${key}:${encodeKey(context[key].key)}`)
         .join(':');
     }
   }