reintroduce searching by most recent

api/resolvers/search.js

@@ -177,23 +177,7 @@ export default {
         whatArr.push({ match: { 'sub.name': sub } })
       }
 
-      let sortField
-      switch (sort) {
-        case 'comments':
-          sortField = 'ncomments'
-          break
-        case 'sats':
-          sortField = 'sats'
-          break
-        default:
-          sortField = 'wvotes'
-          break
-      }
-
-      if (query.length) {
-        whatArr.push({
-          bool: {
-            should: [
+      const should = [
         {
           // all terms are matched in fields
           multi_match: {
@@ -213,8 +197,44 @@ export default {
             minimum_should_match: '60%',
             boost: 1000
           }
-              },
+        }
+      ]
+
+      let boostMode = 'multiply'
+      let sortField
+      let sortMod = 'log1p'
+      switch (sort) {
+        case 'comments':
+          sortField = 'ncomments'
+          sortMod = 'square'
+          break
+        case 'sats':
+          sortField = 'sats'
+          break
+        case 'recent':
+          sortField = 'createdAt'
+          sortMod = 'square'
+          boostMode = 'replace'
+          break
+        default:
+          sortField = 'wvotes'
+          sortMod = 'none'
+          break
+      }
+
+      const functions = [
         {
+          field_value_factor: {
+            field: sortField,
+            modifier: sortMod,
+            factor: 1.2
+          }
+        }
+      ]
+
+      // allow fuzzy matching for single terms
+      if (sort !== 'recent') {
+        should.push({
           // only some terms must match unless we're sorting
           multi_match: {
             query,
@@ -224,8 +244,21 @@ export default {
             prefix_length: 3,
             minimum_should_match: '60%'
           }
+        })
+        // small bias toward posts with comments
+        functions.push({
+          field_value_factor: {
+            field: 'ncomments',
+            modifier: 'ln1p',
+            factor: 1
           }
-            ]
+        })
+      }
+
+      if (query.length) {
+        whatArr.push({
+          bool: {
+            should
           }
         })
       }
@@ -282,23 +315,8 @@ export default {
                     ]
                   }
                 },
-                functions: [
-                  {
-                    field_value_factor: {
-                      field: sortField,
-                      modifier: sort === 'comments' ? 'square' : 'log2p',
-                      factor: 1.2
-                    }
-                  },
-                  {
-                    field_value_factor: {
-                      field: 'ncomments',
-                      modifier: 'ln1p',
-                      factor: 1
-                    }
-                  }
-                ],
-                boost_mode: 'multiply'
+                functions,
+                boost_mode: boostMode
               }
             },
             highlight: {

components/search.js

@@ -97,7 +97,7 @@ export default function Search ({ sub }) {
                         name='sort'
                         size='sm'
                         overrideValue={sort}
-                        items={['zaprank', 'comments', 'sats']}
+                        items={['zaprank', 'recent', 'comments', 'sats']}
                       />
                       for
                       <Select