From 45ea5d0bfeae4b3cb28fe60ad80c180f2151149d Mon Sep 17 00:00:00 2001
From: Brown <github@muglug.com>
Date: Fri, 12 Jun 2020 11:18:34 -0400
Subject: [PATCH] Add a couple more shortcuts for common pattern

Fixes #3563
---
 .../Statements/Expression/AssertionFinder.php |  2 +-
 src/Psalm/Type/Algebra.php                    | 39 ++++++++++++++++++-
 tests/SwitchTypeTest.php                      |  9 +++++
 3 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
index 3223a9891..9d21caba1 100644
--- a/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
+++ b/src/Psalm/Internal/Analyzer/Statements/Expression/AssertionFinder.php
@@ -2367,7 +2367,7 @@ class AssertionFinder
      *
      * @return  int|null
      */
-    protected static function hasTrueVariable(PhpParser\Node\Expr\BinaryOp $conditional)
+    public static function hasTrueVariable(PhpParser\Node\Expr\BinaryOp $conditional)
     {
         if ($conditional->right instanceof PhpParser\Node\Expr\ConstFetch
             && strtolower($conditional->right->name->parts[0]) === 'true'
diff --git a/src/Psalm/Type/Algebra.php b/src/Psalm/Type/Algebra.php
index 12c85fe6a..efaeb3ca4 100644
--- a/src/Psalm/Type/Algebra.php
+++ b/src/Psalm/Type/Algebra.php
@@ -258,8 +258,11 @@ class Algebra
             }
         }
 
-        if ($conditional instanceof PhpParser\Node\Expr\BinaryOp\Identical) {
+        if ($conditional instanceof PhpParser\Node\Expr\BinaryOp\Identical
+            || $conditional instanceof PhpParser\Node\Expr\BinaryOp\Equal
+        ) {
             $false_pos = AssertionFinder::hasFalseVariable($conditional);
+            $true_pos = AssertionFinder::hasTrueVariable($conditional);
 
             if ($false_pos === AssertionFinder::ASSIGNMENT_TO_RIGHT
                 && ($conditional->left instanceof PhpParser\Node\Expr\BinaryOp\BooleanAnd
@@ -276,7 +279,9 @@ class Algebra
                     $inside_negation,
                     $cache
                 );
-            } elseif ($false_pos === AssertionFinder::ASSIGNMENT_TO_LEFT
+            }
+
+            if ($false_pos === AssertionFinder::ASSIGNMENT_TO_LEFT
                 && ($conditional->right instanceof PhpParser\Node\Expr\BinaryOp\BooleanAnd
                     || $conditional->right instanceof PhpParser\Node\Expr\BinaryOp\BooleanOr)
             ) {
@@ -292,6 +297,36 @@ class Algebra
                     $cache
                 );
             }
+
+            if ($true_pos === AssertionFinder::ASSIGNMENT_TO_RIGHT
+                && ($conditional->left instanceof PhpParser\Node\Expr\BinaryOp\BooleanAnd
+                    || $conditional->left instanceof PhpParser\Node\Expr\BinaryOp\BooleanOr)
+            ) {
+                return self::getFormula(
+                    $object_id,
+                    $conditional->left,
+                    $this_class_name,
+                    $source,
+                    $codebase,
+                    $inside_negation,
+                    $cache
+                );
+            }
+
+            if ($true_pos === AssertionFinder::ASSIGNMENT_TO_LEFT
+                && ($conditional->right instanceof PhpParser\Node\Expr\BinaryOp\BooleanAnd
+                    || $conditional->right instanceof PhpParser\Node\Expr\BinaryOp\BooleanOr)
+            ) {
+                return self::getFormula(
+                    $object_id,
+                    $conditional->right,
+                    $this_class_name,
+                    $source,
+                    $codebase,
+                    $inside_negation,
+                    $cache
+                );
+            }
         }
 
         $assertions = null;
diff --git a/tests/SwitchTypeTest.php b/tests/SwitchTypeTest.php
index dcda1dcc9..7933f7684 100644
--- a/tests/SwitchTypeTest.php
+++ b/tests/SwitchTypeTest.php
@@ -861,6 +861,15 @@ class SwitchTypeTest extends TestCase
                         }
                     }'
             ],
+            'switchTruthyWithBoolean' => [
+                '<?php
+                    $a = rand(0,1) ? new \DateTime() : null;
+
+                    switch(true) {
+                        case $a !== null && $a->format("Y") === "2020":
+                            $a->format("d-m-Y");
+                    }'
+            ],
         ];
     }