search: Simplify `narrow_or_search_for_term` code path.

The main reasoning for this change is as follows:

    * When the search bar contains multiple search queries
        but no search results, the last search operand does
        not get displayed.

        This happens due to the fact that filter object
        contained 2 terms having the operator key value as
        "search" instead of a single term where operator is
        "search" and operand is a single string containing
        the space seperated search queries. This condition
        occurs for search_pills_enabled case only because
        we used to Filter.parse the query twice
        (once for the `base_operators` and once for the
        `suggestion_operator instead of doing both at once).

        Thus the `search_query` value inside the
        `narrow.show_search_query` function which only
        selected the operands of the first term displayed
        an incomplete result.

    * Another benefit of this commit is to display the narrow
        operators in the URL fragment the same way as when
        search_pills_enabled = False.

        For example, On entering the queries in the mentioned
        order -> 'is: starred', 'abc', 'def', 'is: private',
        'ghi'. This is the URL:

        Previously:
        /#narrow/is/starred/is/private/search/abc.20def/search/ghi

        Now (same as pills disabled case):
        /#narrow/is/starred/is/private/search/abc.20def.20ghi

    * We are also able to de-duplicate the non-typeahead search
        query code path.

frontend_tests/node_tests/search.js

@@ -20,6 +20,7 @@ set_global('ui_util', {
 set_global('narrow', {});
 
 search_pill.append_search_string = noop;
+search_pill.get_search_string_for_current_filter = noop;
 
 global.patch_builtin('setTimeout', func => func());
 
@@ -139,7 +140,7 @@ run_test('initizalize', () => {
                     assert.deepEqual(options, {trigger: 'search'});
                 };
                 search_pill.get_search_string_for_current_filter = () => {
-                    return '';
+                    return search_box_val;
                 };
             };
 
@@ -150,7 +151,7 @@ run_test('initizalize', () => {
             }];
             _setup('ver');
             opts.updater('ver');
-            assert(is_blurred);
+            assert(!is_blurred);
             assert(is_append_search_string_called);
 
             operators = [{
@@ -160,7 +161,7 @@ run_test('initizalize', () => {
             }];
             _setup('stream:Verona');
             opts.updater('stream:Verona');
-            assert(is_blurred);
+            assert(!is_blurred);
             assert(is_append_search_string_called);
 
             search.is_using_input_method = true;
@@ -206,7 +207,7 @@ run_test('initizalize', () => {
                 assert.deepEqual(options, {trigger: 'search'});
             };
             search_pill.get_search_string_for_current_filter = () => {
-                return '';
+                return search_box_val;
             };
         };
 

static/js/search.js

@@ -1,7 +1,7 @@
 // Exported for unit testing
 exports.is_using_input_method = false;
 
-function narrow_or_search_for_term(search_string) {
+exports.narrow_or_search_for_term = function (search_string) {
     const search_query_box = $("#search_query");
     if (exports.is_using_input_method) {
         // Neither narrow nor search when using input tools as
@@ -13,14 +13,12 @@ function narrow_or_search_for_term(search_string) {
 
     let operators;
     if (page_params.search_pills_enabled) {
-        // search_string only contains the suggestion selected
+        // We have to take care to append the new pill before calling this
-        // from the typeahead. base_query stores the query
+        // function, so that the base_query includes the suggestion selected
-        // corresponding to the existing pills.
+        // along with query corresponding to the existing pills.
         const base_query = search_pill.get_search_string_for_current_filter(
             search_pill_widget.widget);
-        const base_operators = Filter.parse(base_query);
+        operators = Filter.parse(base_query);
-        const suggestion_operator = Filter.parse(search_string);
-        operators = base_operators.concat(suggestion_operator);
     } else {
         operators = Filter.parse(search_string);
     }
@@ -32,9 +30,11 @@ function narrow_or_search_for_term(search_string) {
 
     // Narrowing will have already put some operators in the search box,
     // so leave the current text in.
+    if (!page_params.search_pills_enabled) {
         search_query_box.blur();
-    return search_query_box.val();
     }
+    return search_query_box.val();
+};
 
 function update_buttons_with_focus(focused) {
     const search_query_box = $('#search_query');
@@ -90,22 +90,11 @@ exports.initialize = function () {
             return true;
         },
         updater: function (search_string) {
-            // Order is important here. narrow_or_search_for_term
-            // gets a search string from existing pills and obtains
-            // existing operators. Newly selected suggestion is added
-            // to those operators. If narrow_or_search_for_term was
-            // called after append_search_string, the existing search
-            // pills at the time for calling that function would also
-            // have the newly selected suggestion, and appending it again
-            // would cause duplication.
-            const result = narrow_or_search_for_term(search_string);
             if (page_params.search_pills_enabled) {
                 search_pill.append_search_string(search_string,
                                                  search_pill_widget.widget);
-                $("#search_query").focus();
-            } else {
-                return result;
             }
+            return exports.narrow_or_search_for_term(search_string);
         },
         sorter: function (items) {
             return items;
@@ -150,16 +139,8 @@ exports.initialize = function () {
             // this codepath is that they first all blur the box to
             // indicate that they've done what they need to do)
 
-            let operators = Filter.parse(search_query_box.val());
-            if (page_params.search_pills_enabled) {
             // Pill is already added during keydown event of input pills.
-                // Thus we can't call narrow_or_search_for_term as the
+            exports.narrow_or_search_for_term(search_query_box.val());
-                // search_query_box has empty value.
-                const base_query = search_pill.get_search_string_for_current_filter(
-                    search_pill_widget.widget);
-                operators = Filter.parse(base_query);
-            }
-            narrow.activate(operators, {trigger: 'search'});
             search_query_box.blur();
             update_buttons_with_focus(false);
         }

static/js/search_pill_widget.js

@@ -6,9 +6,7 @@ exports.initialize = function () {
     exports.widget = search_pill.create_pills(container);
 
     exports.widget.onPillRemove(function () {
-        const base_query = search_pill.get_search_string_for_current_filter(exports.widget);
+        search.narrow_or_search_for_term();
-        const operators = Filter.parse(base_query);
-        narrow.activate(operators, {trigger: 'search'});
     });
 };