Make nicer slugs for "sender" narrows.

Slugs are now like our "pm-with" slugs:

    narrow/sender/3-cordelia

frontend_tests/node_tests/hashchange.js

@@ -1,3 +1,9 @@
+global.stub_out_jquery();
+
+add_dependencies({
+    people: 'js/people.js',
+});
+
 var hashchange = require('js/hashchange.js');
 
 (function test_operators_round_trip() {
@@ -32,3 +38,32 @@ var hashchange = require('js/hashchange.js');
     ]);
 
 }());
+
+(function test_people_slugs() {
+    var operators;
+    var hash;
+    var narrow;
+
+    var alice = {
+        email: 'alice@example.com',
+        user_id: 42,
+        full_name: 'Alice Smith',
+    };
+
+    people.add(alice);
+    operators = [
+        {operator: 'sender', operand: 'alice@example.com'},
+    ];
+    hash = hashchange.operators_to_hash(operators);
+    assert.equal(hash, '#narrow/sender/42-alice');
+    narrow = hashchange.parse_narrow(hash.split('/'));
+    assert.deepEqual(narrow, [
+        {operator: 'sender', operand: 'alice@example.com', negated: false},
+    ]);
+
+    operators = [
+        {operator: 'pm-with', operand: 'alice@example.com'},
+    ];
+    hash = hashchange.operators_to_hash(operators);
+    assert.equal(hash, '#narrow/pm-with/42-alice');
+}());

frontend_tests/node_tests/narrow.js

@@ -128,6 +128,9 @@ function set_filter(operators) {
     uri = narrow.huddle_with_uri("22,23");
     assert.equal(uri, '#narrow/pm-with/22,23-group');
 
+    uri = narrow.by_sender_uri(ray.email);
+    assert.equal(uri, '#narrow/sender/22-ray');
+
     var emails = global.hashchange.decode_operand('pm-with', '22,23-group');
     assert.equal(emails, 'alice@example.com,ray@example.com');
 }());

static/js/hashchange.js

@@ -16,7 +16,7 @@ exports.encodeHashComponent = function (str) {
 };
 
 exports.encode_operand = function (operator, operand) {
-    if (operator === 'pm-with') {
+    if ((operator === 'pm-with') || (operator === 'sender')) {
         var slug = people.emails_to_slug(operand);
         if (slug) {
             return slug;
@@ -31,7 +31,7 @@ function decodeHashComponent(str) {
 }
 
 exports.decode_operand = function (operator, operand) {
-    if (operator === 'pm-with') {
+    if ((operator === 'pm-with') || (operator === 'sender')) {
         var emails = people.slug_to_emails(operand);
         if (emails) {
             return emails;

static/js/narrow.js

@@ -598,7 +598,9 @@ exports.huddle_with_uri = function (user_ids_string) {
 };
 
 exports.by_sender_uri = function (reply_to) {
-    return "#narrow/sender/" + hashchange.encodeHashComponent(reply_to);
+    return hashchange.operators_to_hash([
+        {operator: 'sender', operand: reply_to},
+    ]);
 };
 
 exports.by_stream_uri = function (stream) {