bare searching for username; missing commenter explanation

app/models/search.rb

@@ -124,7 +124,7 @@ class Search
     parse_tree.each do |node|
       type, value = node.first
       case type
-      when :commenter
+      when :commenter, :user
         n_commenters += 1
         return invalid("A comment only has one commenter") if n_commenters > 1
         query.joins!(:user).where!(users: {username: value.to_s})
@@ -240,7 +240,7 @@ class Search
         n_domains += 1
         return invalid("A story can't be from multiple domains at once") if n_domains > 1
         query.joins!(:domain).where!(domains: {domain: value.to_s})
-      when :submitter
+      when :submitter, :user
         n_submitters += 1
         return invalid("A story only has one submitter") if n_submitters > 1
         query.joins!(:user).where!(user: {username: value.to_s})

app/models/search_parser.rb

@@ -25,6 +25,8 @@ class SearchParser < Parslet::Parser
       match("[A-Za-z0-9\\-_.:@/()%~?&=#]").repeat(1)
     ).as(:url) >> space?
   }
+  # User::VALID_USERNAME
+  rule(:user) { match("[@~]") >> match("[A-Za-z0-9_\\-]").repeat(1, 24).as(:user) >> space? }
   rule(:negated) { str("-") >> (domain | tag | quoted | term).as(:negated) >> space? }
 
   # catchall consumes ill-structured input
@@ -36,9 +38,9 @@ class SearchParser < Parslet::Parser
       domain |
       submitter |
       tag |
-      # title before quoted so that doesn't consume the quotes
-      title |
+      title | # title before quoted so that doesn't consume the quotes
       url |
+      user | # user must come after commenter and submitter
       # term and quoted after operators they would fail to consume
       term |
       quoted |

app/views/search/index.html.erb

@@ -58,8 +58,10 @@
             type, value = node.first
 
             case type
-            when :domain
-        %>
+          when :commenter %>
+          <dt><span class="searchq">commenter:<%= value %></span></dt>
+          <dd>Comment by: <%= link_to value, user_path(value) %></dd>
+        <% when :domain %>
           <dt><span class="searchq">domain:<%= value %></span></dt>
           <dd>Domain: <%= link_to value, domain_path(value) %></dd>
         <% when :submitter %>
@@ -71,6 +73,9 @@
         <% when :title %>
           <dt><span class="searchq">title:<%= @search.flatten_title(value) %></span></dt>
           <dd>Title: <%= @search.flatten_title(value) %></dd>
+        <% when :user %>
+          <dt><span class="searchq">@<%= value %></span></dt>
+          <dd><%= @search.searched_model.name %> by: <%= link_to value, user_path(value) %></dd>
         <% when :negated %>
         <% when :quoted %>
           <dt><span class="searchq">"<%= value %>"</span></dt>

spec/models/search_parser_spec.rb

@@ -65,6 +65,13 @@ describe SearchParser do
     it("parses multiple words") { expect(sp.quoted).to parse('"research words"') }
   end
 
+  describe "commenter rule" do
+    it("parses username") { expect(sp.commenter).to parse("commenter:alice") }
+    it("parses with @") { expect(sp.commenter).to parse("commenter:@bob") }
+    it("parses with ~") { expect(sp.commenter).to parse("commenter:~carol") }
+    it("doesn't parse blank") { expect(sp.commenter).to_not parse("commenter:") }
+  end
+
   describe "domain rule" do
     it("parses single") { expect(sp.domain).to parse("domain:example.com") }
     it("parses dash") { expect(sp.domain).to parse("domain:foo-bar.com") }
@@ -90,6 +97,14 @@ describe SearchParser do
     it("parses punctuation stripped from terms") { expect(sp.url).to parse("https://example.com/foo-bar&a=b") }
   end
 
+  describe "user rule" do
+    it("parses with @") { expect(sp.user).to parse("@bob") }
+    it("parses with ~") { expect(sp.user).to parse("~carol") }
+    it("doesn't parse blank @") { expect(sp.user).to_not parse("@") }
+    it("doesn't parse emails") { expect(sp.user).to_not parse("user@example.com") }
+    it("doesn't parse blank ~") { expect(sp.user).to_not parse("~") }
+  end
+
   describe "title rule" do
     it("parses single") { expect(sp.title).to parse("title:seven") }
     it("does parse single word quote") { expect(sp.title).to parse('title:"tips"') }