fix: stringify scalar columns to match stock wpdb's mysqli typing

The bridge returns native int/float, but mysqli returns every scalar
column as a string (mysqlnd only types natively under
MYSQLI_OPT_INT_AND_FLOAT_NATIVE, which wpdb never sets). Core and
plugins strict-compare against those strings — wp-includes/blocks/
comments-title.php does '0' === get_comments_number(), so native ints
made every comment-less post render a spurious "0 responses" heading.
Found by byte-diffing rendered HTML against stock wpdb under real
WordPress.

Stringify non-NULL scalars during row hydration (floats via PHP's
default float-to-string conversion; NULL stays null), fix the README
claim that native types survive, and add a regression test asserting
COUNT(*) comes back as string "0" with the exact comments-title strict
compare, plus a non-integral float case.

Author: luthermonson

README.md

@@ -166,9 +166,17 @@ on the state this class populates.
 | mysqli pass-through (`$wpdb->dbh`, `mysqli_result` access) | **not supported** — `$dbh` is always `null`; code that reaches into it for raw mysqli calls will not work |
 | `get_col_length()` | **degraded** — always returns `false` (no `SHOW FULL COLUMNS` interrogation), so core skips its PHP-side length truncation. SQLite does not enforce `VARCHAR(n)` lengths anyway |
 
-Native types survive the bridge: integer columns arrive as PHP `int`,
-floats as `float`, `NULL` as `null` — same as mysqlnd with default
-settings.
+**Result typing matches stock wpdb: every scalar column is a string.**
+mysqli returns all scalars as strings unless
+`MYSQLI_OPT_INT_AND_FLOAT_NATIVE` is set — and wpdb never sets it — so
+core and plugins strict-compare against string values (core's
+comments-title block does `'0' === get_comments_number()`, for
+example). The bridge itself hands back native `int`/`float`, and the
+drop-in deliberately stringifies them during row hydration to preserve
+that contract; `NULL` stays `null`, exactly as under mysqli. Floats use
+PHP's default float-to-string conversion. Exposing the bridge's native
+typing could become an explicit opt-in in a future release — it is not
+implemented today.
 
 ---
 
@@ -332,7 +340,9 @@ database via the embed SAPI. [ephpm#257](https://github.com/ephpm/ephpm/pull/257
 registered two host functions into PHP's global function table:
 
 - `ephpm_db_query(string $sql, array $params = []): array` — rows as a
-  list of associative arrays; int/float/null arrive as native PHP types.
+  list of associative arrays; int/float/null arrive as native PHP types
+  (which the drop-in stringifies during hydration to match stock wpdb —
+  see [What is implemented](#what-is-implemented)).
 - `ephpm_db_execute(string $sql, array $params = []): array` —
   `{affected_rows, last_insert_id}`.
 

src/Db.php

@@ -218,6 +218,23 @@ public function query($query)
             $num_rows = 0;
 
             foreach ($this->bridgeRows ?? [] as $row) {
+                /*
+                 * Match stock wpdb's typing contract exactly: mysqli
+                 * returns EVERY scalar column as a string (mysqlnd only
+                 * types natively under MYSQLI_OPT_INT_AND_FLOAT_NATIVE,
+                 * which wpdb never sets). The bridge hands us native
+                 * int/float, so stringify them here — core and plugins
+                 * strict-compare against string values (e.g.
+                 * `'0' === get_comments_number()` in the comments-title
+                 * block) and native types break those paths. NULL stays
+                 * null, as it does under mysqli. Floats use PHP's default
+                 * float-to-string conversion.
+                 */
+                foreach ($row as $col => $value) {
+                    if (null !== $value && !\is_string($value)) {
+                        $row[$col] = (string) $value;
+                    }
+                }
                 $this->last_result[$num_rows] = (object) $row;
                 ++$num_rows;
             }

tests/DbTest.php

@@ -120,17 +120,17 @@ public function testGetResultsObjectArrayAAndArrayN(): void
         $this->assertCount(1, $objects);
         $this->assertInstanceOf(\stdClass::class, $objects[0]);
         $this->assertSame('widget', $objects[0]->name);
-        $this->assertSame(1, $objects[0]->id);       // Native int, not "1".
-        $this->assertSame(3, $objects[0]->qty);
-        $this->assertSame(1.5, $objects[0]->price);  // Native float.
-        $this->assertNull($objects[0]->note);        // SQL NULL -> null.
+        $this->assertSame('1', $objects[0]->id);      // String, like mysqli.
+        $this->assertSame('3', $objects[0]->qty);
+        $this->assertSame('1.5', $objects[0]->price); // String, like mysqli.
+        $this->assertNull($objects[0]->note);         // SQL NULL -> null.
         $this->assertSame(1, $db->num_rows);
 
         $assoc = $db->get_results('SELECT id, name FROM wp_items', ARRAY_A);
-        $this->assertSame([['id' => 1, 'name' => 'widget']], $assoc);
+        $this->assertSame([['id' => '1', 'name' => 'widget']], $assoc);
 
         $numeric = $db->get_results('SELECT id, name FROM wp_items', ARRAY_N);
-        $this->assertSame([[1, 'widget']], $numeric);
+        $this->assertSame([['1', 'widget']], $numeric);
     }
 
     public function testGetRowGetVarGetCol(): void
@@ -144,9 +144,9 @@ public function testGetRowGetVarGetCol(): void
         $this->assertSame('widget', $row->name);
 
         $rowA = $db->get_row('SELECT name, qty FROM wp_items ORDER BY id LIMIT 1', ARRAY_A);
-        $this->assertSame(['name' => 'widget', 'qty' => 3], $rowA);
+        $this->assertSame(['name' => 'widget', 'qty' => '3'], $rowA);
 
-        $this->assertSame(10, $db->get_var('SELECT SUM(qty) FROM wp_items'));
+        $this->assertSame('10', $db->get_var('SELECT SUM(qty) FROM wp_items'));
         $this->assertSame(['widget', 'gadget'], $db->get_col('SELECT name FROM wp_items ORDER BY id'));
         $this->assertNull($db->get_var('SELECT name FROM wp_items WHERE qty = 999'));
     }
@@ -242,7 +242,32 @@ public function testPreparePlaceholders(): void
         $this->assertStringContainsString('`wp_items`', $sql);
         $this->assertStringContainsString("'it\\'s'", $sql);
 
-        $this->assertSame(5, $db->get_var($sql));
+        $this->assertSame('5', $db->get_var($sql));
+    }
+
+    /**
+     * Regression: stock wpdb returns every scalar column as a string
+     * (mysqli without MYSQLI_OPT_INT_AND_FLOAT_NATIVE, which wpdb never
+     * sets). Core strict-compares against those strings — e.g. the
+     * comments-title block does `'0' === get_comments_number()` — so
+     * native int/float hydration renders wrong output. NULL must stay
+     * null, exactly as under mysqli.
+     */
+    public function testScalarColumnsComeBackAsStringsLikeStockWpdb(): void
+    {
+        $db = $this->makeDbWithTable();
+        $db->insert('wp_items', ['name' => 'post']);
+
+        $count = $db->get_var(
+            "SELECT COUNT(*) FROM wp_items WHERE name = 'no-such-comment'"
+        );
+        $this->assertSame('0', $count);
+        $this->assertTrue('0' === $count); // The comments-title comparison.
+
+        // Non-integral float: PHP's default float-to-string conversion.
+        $db->insert('wp_items', ['name' => 'priced', 'qty' => 7, 'price' => 2.25], ['%s', '%d', '%f']);
+        $row = $db->get_row("SELECT qty, price, note FROM wp_items WHERE name = 'priced'", ARRAY_A);
+        $this->assertSame(['qty' => '7', 'price' => '2.25', 'note' => null], $row);
     }
 
     public function testPreparedLikeWithEscapedPercentLiteral(): void
@@ -302,12 +327,12 @@ public function testTransactionsFlowThroughAsSql(): void
         $db->query('BEGIN');
         $db->insert('wp_items', ['name' => 'temp']);
         $db->query('ROLLBACK');
-        $this->assertSame(0, $db->get_var('SELECT COUNT(*) FROM wp_items'));
+        $this->assertSame('0', $db->get_var('SELECT COUNT(*) FROM wp_items'));
 
         $db->query('BEGIN');
         $db->insert('wp_items', ['name' => 'kept']);
         $db->query('COMMIT');
-        $this->assertSame(1, $db->get_var('SELECT COUNT(*) FROM wp_items'));
+        $this->assertSame('1', $db->get_var('SELECT COUNT(*) FROM wp_items'));
     }
 
     public function testLeadingCommentRouting(): void