Optional rule to disable float in every expression (not just assignments)

composer.json

@@ -7,7 +7,7 @@
     "require": {
         "php": "^7.2",
         "nikic/php-parser": "^4.0",
-        "phpstan/phpstan": "^0.10"
+        "phpstan/phpstan": "^0.10.8"
     },
     "require-dev": {
         "doctrine/coding-standard": "^5.0.0",

rules.neon

@@ -3,3 +3,14 @@ rules:
 	- Roave\PHPStan\Rules\Floats\DisallowFloatInFunctionSignatureRule
 	- Roave\PHPStan\Rules\Floats\DisallowFloatInMethodSignatureRule
 	- Roave\PHPStan\Rules\Floats\DisallowFloatPropertyTypeRule
+
+parameters:
+	disallowFloatsEverywhere: false
+
+conditionalTags:
+	Roave\PHPStan\Rules\Floats\DisallowFloatEverywhereRule:
+		phpstan.rules.rule: %disallowFloatsEverywhere%
+
+services:
+	-
+		class: Roave\PHPStan\Rules\Floats\DisallowFloatEverywhereRule

src/DisallowFloatEverywhereRule.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Roave\PHPStan\Rules\Floats;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr;
+use PHPStan\Analyser\Scope;
+use PHPStan\Rules\Rule;
+use PHPStan\Type\VerbosityLevel;
+use function sprintf;
+
+class DisallowFloatEverywhereRule implements Rule
+{
+    public function getNodeType() : string
+    {
+        return Node\Expr::class;
+    }
+
+    /**
+     * @param Expr $node
+     *
+     * @return string[]
+     */
+    public function processNode(Node $node, Scope $scope) : array
+    {
+        if ($node instanceof Node\Expr\AssignOp
+            || $node instanceof Node\Expr\Assign
+        ) {
+            return [];
+        }
+
+        $nodeType = $scope->getType($node);
+        if (! FloatTypeHelper::isFloat($nodeType)) {
+            return [];
+        }
+
+        return [
+            sprintf(
+                'Cannot have %s as a result type of this expression - floats are not allowed.',
+                $nodeType->describe(VerbosityLevel::typeOnly())
+            ),
+        ];
+    }
+}

tests/asset/assign.php

@@ -24,4 +24,11 @@ public function doFoo($float, $intOrFloat, string $str)
         $test3 = $str;
     }
 
+    public function doBar()
+    {
+        $test = 0;
+        $test += 1;
+        $test += 3.14;
+    }
+
 }

tests/asset/expr.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace DisallowFloatsEverywhere;
+
+function () {
+    $foo = 1.3;
+    $foo += 1.3;
+
+    foo(
+        3.14
+    );
+};

tests/src/DisallowFloatAssignedToVariableRuleTest.php

@@ -35,6 +35,10 @@ public function testRule() : void
                 'Cannot assign float to $this->bar[\'test\'] - floats are not allowed.',
                 22,
             ],
+            [
+                'Cannot assign float to $test - floats are not allowed.',
+                31,
+            ],
         ]);
     }
 }

tests/src/DisallowFloatEverywhereRuleTest.php

@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Roave\PHPStanTest\Rules\Floats;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+use Roave\PHPStan\Rules\Floats\DisallowFloatEverywhereRule;
+
+class DisallowFloatEverywhereRuleTest extends RuleTestCase
+{
+    protected function getRule() : Rule
+    {
+        return new DisallowFloatEverywhereRule();
+    }
+
+    public function testRule() : void
+    {
+        $this->analyse([__DIR__ . '/../asset/expr.php'], [
+            [
+                'Cannot have float as a result type of this expression - floats are not allowed.',
+                6,
+            ],
+            [
+                'Cannot have float as a result type of this expression - floats are not allowed.',
+                7,
+            ],
+            [
+                'Cannot have float as a result type of this expression - floats are not allowed.',
+                7,
+            ],
+            [
+                'Cannot have float as a result type of this expression - floats are not allowed.',
+                10,
+            ],
+        ]);
+    }
+}