From d1740394aa2e4313900c0d6a2be9f6da7b03c3c7 Mon Sep 17 00:00:00 2001
From: Matt Brown <github@muglug.com>
Date: Sat, 20 Mar 2021 20:53:51 -0400
Subject: [PATCH] Detect mixed echo argument when unused variable detection is
 turned on

---
 .../Analyzer/Statements/EchoAnalyzer.php      | 22 +++++++++----------
 tests/UnusedVariableTest.php                  |  8 ++++++-
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/EchoAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/EchoAnalyzer.php
index 7a9e3fce57e..b63ee750f8e 100644
--- a/src/Psalm/Internal/Analyzer/Statements/EchoAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/EchoAnalyzer.php
@@ -37,19 +37,17 @@ public static function analyze(
 
             $expr_type = $statements_analyzer->node_data->getType($expr);
 
-            if ($statements_analyzer->data_flow_graph
-                && $expr_type
-            ) {
-                $expr_type = CastAnalyzer::castStringAttempt(
-                    $statements_analyzer,
-                    $context,
-                    $expr_type,
-                    $expr,
-                    false
-                );
-            }
-
             if ($statements_analyzer->data_flow_graph instanceof TaintFlowGraph) {
+                if ($expr_type) {
+                    $expr_type = CastAnalyzer::castStringAttempt(
+                        $statements_analyzer,
+                        $context,
+                        $expr_type,
+                        $expr,
+                        false
+                    );
+                }
+
                 $call_location = new CodeLocation($statements_analyzer->getSource(), $stmt);
 
                 $echo_param_sink = TaintSink::getForMethodArgument(
diff --git a/tests/UnusedVariableTest.php b/tests/UnusedVariableTest.php
index 794722cda11..9681871b3d8 100644
--- a/tests/UnusedVariableTest.php
+++ b/tests/UnusedVariableTest.php
@@ -932,6 +932,7 @@ function bar(string $type) : ArrayObject {
                         $i = 1;
                     };
                     $a();
+                    /** @psalm-suppress MixedArgument */
                     echo $i;',
             ],
             'regularVariableClosureUseInAddition' => [
@@ -1853,7 +1854,10 @@ function foo(string $a): void {
                             $hue = "goodbye";
                         }
 
-                        /** @psalm-suppress PossiblyUndefinedVariable */
+                        /**
+                         * @psalm-suppress PossiblyUndefinedVariable
+                         * @psalm-suppress MixedArgument
+                         */
                         echo $hue;
                     }'
             ],
@@ -1928,6 +1932,7 @@ function foo(int $i): void {
                         }
 
                         if (isset($j)) {
+                            /** @psalm-suppress MixedArgument */
                             echo $j;
                         }
                     }'
@@ -2012,6 +2017,7 @@ function verifyLoad(bool $b) : bool {
                 '<?php
                     /**
                      * @psalm-suppress MixedAssignment
+                     * @psalm-suppress MixedArgument
                      * @param iterable<mixed, int> $keys
                      */
                     function foo(iterable $keys, int $colno) : void {