Fix helper calls in complex subexpressions

Author: theodorejb

src/Compiler.php

@@ -526,25 +526,8 @@ private function MustacheStatement(MustacheStatement $mustache): string
         $type = $this->classifySexpr($helperName, $mustache->params, $mustache->hash);
 
         if ($type === SexprType::Helper) {
-            if ($helperName !== null) {
-                $call = $this->buildInlineHelperCall($helperName, $mustache->params, $mustache->hash);
-                return self::getRuntimeFunc($fn, $call);
-            }
-            // Complex PathExpression with params: route through resolveHelper+hbch so helperMissing fires,
-            // or dv() for data/depth/scoped paths where helper dispatch does not apply.
-            if ($path instanceof PathExpression) {
-                $varPath = $this->PathExpression($path);
-                $stringParts = array_filter($path->parts, 'is_string');
-                if (!$path->data && $path->depth === 0 && !self::scopedId($path)
-                    && count($stringParts) === count($path->parts)) {
-                    $logicalName = self::quote(implode('.', $stringParts));
-                    $compiledParams = $this->compileParams($mustache->params, $mustache->hash);
-                    return self::getRuntimeFunc($fn, $this->buildResolvedHbchCall($logicalName, $varPath, $compiledParams));
-                }
-                $args = array_map(fn($p) => $this->compileExpression($p), $mustache->params);
-                $call = self::getRuntimeFunc('dv', "$varPath, " . implode(', ', $args));
-                return self::getRuntimeFunc($fn, $call);
-            }
+            $call = $this->compileHelperCall($helperName, $path, $mustache->params, $mustache->hash);
+            return self::getRuntimeFunc($fn, $call);
         }
 
         if ($helperName !== null && $type === SexprType::Ambiguous && !$this->context->options->strict) {
@@ -584,17 +567,7 @@ private function SubExpression(SubExpression $expression): string
             ? $this->getSimpleHelperName($path)
             : null;
 
-        if ($helperName === null) {
-            // Dynamic callable: path rooted at a sub-expression, e.g. ((helper).prop args)
-            if ($path instanceof PathExpression) {
-                $varPath = $this->PathExpression($path);
-                $args = array_map(fn($p) => $this->compileExpression($p), $expression->params);
-                return self::getRuntimeFunc('dv', implode(', ', [$varPath, ...$args]));
-            }
-            throw new \Exception('Sub-expression must be a helper call');
-        }
-
-        return $this->buildInlineHelperCall($helperName, $expression->params, $expression->hash);
+        return $this->compileHelperCall($helperName, $path, $expression->params, $expression->hash);
     }
 
     private function PathExpression(PathExpression $expression): string
@@ -902,6 +875,37 @@ private function buildResolvedHbchCall(string $escapedName, string $varPath, str
         return self::getRuntimeFunc('hbch', "\$cx, $resolved, $escapedName, $params, \$in");
     }
 
+    /**
+     * Compile a helper call for a MustacheStatement (Helper type) or SubExpression.
+     * @param Expression[] $params
+     */
+    private function compileHelperCall(?string $helperName, Expression $path, array $params, ?Hash $hash): string
+    {
+        if ($helperName !== null) {
+            $compiledParams = $this->compileParams($params, $hash);
+            $escapedName = self::quote($helperName);
+            if ($this->isKnownHelper($helperName)) {
+                return self::getRuntimeFunc('hbch', "\$cx, \$cx->helpers[$escapedName], $escapedName, $compiledParams, \$in");
+            }
+            if ($this->context->options->knownHelpersOnly) {
+                $this->throwKnownHelpersOnly($helperName);
+            }
+            return $this->buildResolvedHbchCall($escapedName, "\$in[$escapedName] ?? null", $compiledParams);
+        }
+        if ($path instanceof PathExpression) {
+            $varPath = $this->PathExpression($path);
+            $stringParts = array_filter($path->parts, 'is_string');
+            if (!$path->data && $path->depth === 0 && !self::scopedId($path)
+                && count($stringParts) === count($path->parts)) {
+                $logicalName = self::quote(implode('.', $stringParts));
+                return $this->buildResolvedHbchCall($logicalName, $varPath, $this->compileParams($params, $hash));
+            }
+            $args = array_map(fn($p) => $this->compileExpression($p), $params);
+            return self::getRuntimeFunc('dv', implode(', ', [$varPath, ...$args]));
+        }
+        throw new \Exception('Sub-expression must be a helper call');
+    }
+
     /**
      * Build runtime function call.
      */
@@ -964,21 +968,4 @@ private function throwKnownHelpersOnly(string $helperName): never
     {
         throw new \Exception("You specified knownHelpersOnly, but used the unknown helper $helperName");
     }
-
-    /**
-     * Build an hbch inline helper call string.
-     * @param Expression[] $params
-     */
-    private function buildInlineHelperCall(string $name, array $params, ?Hash $hash): string
-    {
-        $compiledParams = $this->compileParams($params, $hash);
-        $helperName = self::quote($name);
-        if ($this->isKnownHelper($name)) {
-            return self::getRuntimeFunc('hbch', "\$cx, \$cx->helpers[$helperName], $helperName, $compiledParams, \$in");
-        }
-        if ($this->context->options->knownHelpersOnly) {
-            $this->throwKnownHelpersOnly($name);
-        }
-        return $this->buildResolvedHbchCall($helperName, "\$in[$helperName] ?? null", $compiledParams);
-    }
 }

tests/RegressionTest.php

@@ -2277,6 +2277,29 @@ public static function subexpressionPathProvider(): array
                 ],
                 'expected' => 'WORLD',
             ],
+
+            'sub-expression: multi-segment callee invokes helperMissing when not in context' => [
+                'template' => '{{identity (foo.bar baz)}}',
+                'data' => ['baz' => 'val'],
+                'helpers' => [
+                    'identity' => fn($x) => $x,
+                    'helperMissing' => fn($x, HelperOptions $opts) => 'missing:' . $opts->name,
+                ],
+                'expected' => 'missing:foo.bar',
+            ],
+            'sub-expression: multi-segment callee receives HelperOptions' => [
+                'template' => '{{{identity (foo.bar baz)}}}',
+                'data' => [
+                    'foo' => [
+                        'bar' => function ($x, ?HelperOptions $opts = null) {
+                            return 'name=' . ($opts->name ?? 'null') . ',x=' . $x;
+                        },
+                    ],
+                    'baz' => 'val',
+                ],
+                'helpers' => ['identity' => fn($x) => $x],
+                'expected' => 'name=foo.bar,x=val',
+            ],
         ];
     }