Search: Added support for escaped exact terms

Also prevented use of empty exact matches.
Prevents issues when attempting to use exact search terms in inputs for
just search terms, and use of single " chars within search terms since
these would get auto-promoted to exacts.

For #4535

app/Search/SearchOptions.php

@@ -44,8 +44,8 @@ class SearchOptions
         $inputs = $request->only(['search', 'types', 'filters', 'exact', 'tags']);
 
         $parsedStandardTerms = static::parseStandardTermString($inputs['search'] ?? '');
-        $instance->searches = $parsedStandardTerms['terms'];
-        $instance->exacts = $parsedStandardTerms['exacts'];
+        $instance->searches = array_filter($parsedStandardTerms['terms']);
+        $instance->exacts = array_filter($parsedStandardTerms['exacts']);
 
         array_push($instance->exacts, ...array_filter($inputs['exact'] ?? []));
 
@@ -78,7 +78,7 @@ class SearchOptions
         ];
 
         $patterns = [
-            'exacts'  => '/"(.*?)"/',
+            'exacts'  => '/"(.*?)(?<!\\\)"/',
             'tags'    => '/\[(.*?)\]/',
             'filters' => '/\{(.*?)\}/',
         ];
@@ -93,6 +93,11 @@ class SearchOptions
             }
         }
 
+        // Unescape exacts
+        foreach ($terms['exacts'] as $index => $exact) {
+            $terms['exacts'][$index] = str_replace('\"', '"', $exact);
+        }
+
         // Parse standard terms
         $parsedStandardTerms = static::parseStandardTermString($searchString);
         array_push($terms['searches'], ...$parsedStandardTerms['terms']);
@@ -106,12 +111,19 @@ class SearchOptions
         }
         $terms['filters'] = $splitFilters;
 
+        // Filter down terms where required
+        $terms['exacts'] = array_filter($terms['exacts']);
+        $terms['searches'] = array_filter($terms['searches']);
+
         return $terms;
     }
 
     /**
      * Parse a standard search term string into individual search terms and
-     * extract any exact terms searches to be made.
+     * convert any required terms to exact matches. This is done since some
+     * characters will never be in the standard index, since we use them as
+     * delimiters, and therefore we convert a term to be exact if it
+     * contains one of those delimiter characters.
      *
      * @return array{terms: array<string>, exacts: array<string>}
      */
@@ -129,8 +141,8 @@ class SearchOptions
                 continue;
             }
 
-            $parsedList = (strpbrk($searchTerm, $indexDelimiters) === false) ? 'terms' : 'exacts';
-            $parsed[$parsedList][] = $searchTerm;
+            $becomeExact = (strpbrk($searchTerm, $indexDelimiters) !== false);
+            $parsed[$becomeExact ? 'exacts' : 'terms'][] = $searchTerm;
         }
 
         return $parsed;
@@ -141,20 +153,21 @@ class SearchOptions
      */
     public function toString(): string
     {
-        $string = implode(' ', $this->searches ?? []);
+        $parts = $this->searches;
 
         foreach ($this->exacts as $term) {
-            $string .= ' "' . $term . '"';
+            $escaped = str_replace('"', '\"', $term);
+            $parts[] = '"' . $escaped . '"';
         }
 
         foreach ($this->tags as $term) {
-            $string .= " [{$term}]";
+            $parts[] = "[{$term}]";
         }
 
         foreach ($this->filters as $filterName => $filterVal) {
-            $string .= ' {' . $filterName . ($filterVal ? ':' . $filterVal : '') . '}';
+            $parts[] = '{' . $filterName . ($filterVal ? ':' . $filterVal : '') . '}';
         }
 
-        return $string;
+        return implode(' ', $parts);
     }
 }

tests/Entity/SearchOptionsTest.php

@@ -3,6 +3,7 @@
 namespace Tests\Entity;
 
 use BookStack\Search\SearchOptions;
+use Illuminate\Http\Request;
 use Tests\TestCase;
 
 class SearchOptionsTest extends TestCase
@@ -17,6 +18,13 @@ class SearchOptionsTest extends TestCase
         $this->assertEquals(['is_tree' => ''], $options->filters);
     }
 
+    public function test_from_string_properly_parses_escaped_quotes()
+    {
+        $options = SearchOptions::fromString('"\"cat\"" surprise "\"\"" "\"donkey" "\""');
+
+        $this->assertEquals(['"cat"', '""', '"donkey', '"'], $options->exacts);
+    }
+
     public function test_to_string_includes_all_items_in_the_correct_format()
     {
         $expected = 'cat "dog" [tag=good] {is_tree}';
@@ -32,6 +40,15 @@ class SearchOptionsTest extends TestCase
         }
     }
 
+    public function test_to_string_escapes_quotes_as_expected()
+    {
+        $options = new SearchOptions();
+        $options->exacts = ['"cat"', '""', '"donkey', '"'];
+
+        $output = $options->toString();
+        $this->assertEquals('"\"cat\"" "\"\"" "\"donkey" "\""', $output);
+    }
+
     public function test_correct_filter_values_are_set_from_string()
     {
         $opts = SearchOptions::fromString('{is_tree} {name:dan} {cat:happy}');
@@ -42,4 +59,22 @@ class SearchOptionsTest extends TestCase
             'cat'     => 'happy',
         ], $opts->filters);
     }
+    public function test_it_cannot_parse_out_empty_exacts()
+    {
+        $options = SearchOptions::fromString('"" test ""');
+
+        $this->assertEmpty($options->exacts);
+        $this->assertCount(1, $options->searches);
+    }
+
+    public function test_from_request_properly_parses_exacts_from_search_terms()
+    {
+        $request = new Request([
+            'search' => 'biscuits "cheese" "" "baked beans"'
+        ]);
+
+        $options = SearchOptions::fromRequest($request);
+        $this->assertEquals(["biscuits"], $options->searches);
+        $this->assertEquals(['"cheese"', '""', '"baked',  'beans"'], $options->exacts);
+    }
 }