Fix multi-segment if/unless condition compilation

Resolves #15

Author: theodorejb

src/Compiler.php

@@ -326,9 +326,10 @@ private function canInlineConditional(BlockStatement $block, string $helperName,
 
     /**
      * Compile the condition expression for an inlined if/unless ternary.
-     * For simple single-segment paths, routes through cv() which already resolves closures,
-     * so ifvar() suffices. For all other expressions, closures at nested paths are not
-     * invoked (not a real-world or spec concern).
+     * Single-segment plain context paths (e.g. {{#if foo}}) use cv() so that closures are
+     * invoked before being tested. All other expressions (multi-segment paths, data variables,
+     * block params, sub-expressions) use compileExpression() as a helper argument.
+     * Closures at nested path segments are not invoked.
      * @param bool $negate true for `unless` or inverted `{{^if}}`
      */
     private function compileConditionalExpr(Expression $condExpr, bool $negate): string
@@ -338,6 +339,7 @@ private function compileConditionalExpr(Expression $condExpr, bool $negate): str
             && !$condExpr->data
             && $condExpr->depth === 0
             && is_string($part)
+            && count($condExpr->parts) === 1
             && !self::scopedId($condExpr)
             && $this->lookupBlockParam($part) === null
         ) {

tests/RegressionTest.php

@@ -1845,6 +1845,21 @@ public static function ifElseProvider(): array
                     _tpl,
                 'expected' => "  Finally, do this last thing if all else fails\n",
             ],
+
+            [
+                'desc' => '#15 - if should work with multi-segment path expression',
+                'template' => '{{#if foo.bar}}bad{{else}}OK{{/if}}',
+                'data' => ['foo' => 'foo'],
+                'expected' => 'OK',
+            ],
+
+            [
+                'desc' => 'strict mode should not throw if the final property of a helper argument is missing',
+                'template' => '{{#if foo.bar}}bad{{else}}OK{{/if}}',
+                'options' => new Options(strict: true),
+                'data' => ['foo' => []],
+                'expected' => 'OK',
+            ],
         ];
     }