Change code block typeahead to only sometimes close fence.

Fixes #5556.
Some tests needed to be moved around to make sure the
stubbing wouldn't break future tests.

frontend_tests/node_tests/composebox_typeahead.js

@@ -191,6 +191,16 @@ global.people.add(deactivated_user);
     expected_value = '```python\n\n```';
     assert.equal(actual_value, expected_value);
 
+    // Test special case to not close code blocks if there is text afterward
+    fake_this.query = '```p\nsome existing code';
+    fake_this.token = 'p';
+    fake_this.$element.caret = function () {
+        return 4; // Put cursor right after ```p
+    };
+    actual_value = ct.content_typeahead_selected.call(fake_this, 'python');
+    expected_value = '```python\nsome existing code';
+    assert.equal(actual_value, expected_value);
+
     fake_this.completing = 'something-else';
 
     fake_this.query = 'foo';

frontend_tests/node_tests/stream_events.js

@@ -0,0 +1,68 @@
+var assert = require('assert');
+var noop = function () {};
+set_global('$', global.make_zjquery());
+
+set_global('colorspace', {
+    sRGB_to_linear: noop,
+    luminance_to_lightness: function () {
+        return 1;
+    },
+});
+
+add_dependencies({
+    stream_events: 'js/stream_events.js',
+    stream_data: 'js/stream_data.js',
+    stream_color: 'js/stream_color.js',
+    util: 'js/util.js',
+});
+
+var stream_events = require('js/stream_events.js');
+var with_overrides = global.with_overrides;
+
+var frontend = {
+    subscribed: true,
+    color: 'yellow',
+    name: 'frontend',
+    stream_id: 1,
+    in_home_view: false,
+    invite_only: false,
+};
+stream_data.add_sub('Frontend', frontend);
+
+(function test_update_property() {
+    // Invoke error for non-existent stream/property
+    with_overrides(function (override) {
+        var errors = 0;
+        override('blueslip.warn', function () {
+            errors += 1;
+        });
+
+        stream_events.update_property(99, 'color', 'blue');
+        assert.equal(errors, 1);
+
+        stream_events.update_property(1, 'not_real', 42);
+        assert.equal(errors, 2);
+    });
+
+    // Test update color
+    with_overrides(function (override) {
+        global.with_stub(function (stub) {
+            override('stream_color.update_stream_color', stub.f);
+            stream_events.update_property(1, 'color', 'blue');
+            var args = stub.get_args('sub', 'val');
+            assert.equal(args.sub.stream_id, 1);
+            assert.equal(args.val, 'blue');
+        });
+    });
+
+    // Test in home view
+    with_overrides(function (override) {
+        global.with_stub(function (stub) {
+            override('stream_muting.update_in_home_view', stub.f);
+            stream_events.update_property(1, 'in_home_view', true);
+            var args = stub.get_args('sub', 'val');
+            assert.equal(args.sub.stream_id, 1);
+            assert.equal(args.val, true);
+        });
+    });
+}());

static/js/composebox_typeahead.js

@@ -349,9 +349,20 @@ exports.content_typeahead_selected = function (item) {
                 + '#**' + item.name + '** ');
         $(document).trigger('streamname_completed.zulip', {stream: item});
     } else if (this.completing === 'syntax') {
-        rest = "\n" + beginning.substring(beginning.length - this.token.length - 4,
-                beginning.length - this.token.length).trim() + rest;
-        beginning = beginning.substring(0, beginning.length - this.token.length) + item + "\n";
+        // Isolate the end index of the triple backticks/tildes, including
+        // possibly a space afterward
+        var backticks = beginning.length - this.token.length;
+        if (rest === '') {
+            // If cursor is at end of input ("rest" is empty), then
+            // complete the token before the cursor, and add a closing fence
+            // after the cursor
+            beginning = beginning.substring(0, backticks) + item + '\n';
+            rest = "\n" + beginning.substring(backticks - 4, backticks).trim() + rest;
+        } else {
+            // If more text after the input, then complete the token, but don't touch
+            // "rest" (i.e. do not add a closing fence)
+            beginning = beginning.substring(0, backticks) + item;
+        }
     }
 
     // Keep the cursor after the newly inserted text, as Bootstrap will call textbox.change() to