diff --git a/README.md b/README.md
index 9c2ffbb..9d77d1c 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,6 @@
 # php-types
+
+[![Build Status](https://travis-ci.com/event-engine/php-types.svg?branch=master)](https://travis-ci.com/event-engine/php-types)
+[![Coverage Status](https://coveralls.io/repos/github/event-engine/php-types/badge.svg?branch=master)](https://coveralls.io/github/event-engine/php-types?branch=master)
+
 PHP 7.4 + psalm powered Immutable Types
diff --git a/src/ImmutableBoolean.php b/src/ImmutableBoolean.php
index 334f241..288953a 100644
--- a/src/ImmutableBoolean.php
+++ b/src/ImmutableBoolean.php
@@ -39,7 +39,7 @@ public static function fromBool(bool $value): self
 
     public function __construct(bool $value)
     {
-        if(isset($this->value)) {
+        if (isset($this->value)) {
             throw new BadMethodCallException(__METHOD__ . ' called on existing object!');
         }
 
@@ -58,11 +58,11 @@ public function __toString(): string
 
     public function equals($value): bool
     {
-        if(is_object($value) && method_exists($value, 'toBool')) {
+        if (is_object($value) && method_exists($value, 'toBool')) {
             return $this->value === $value->toBool();
         }
 
-        if(is_bool($value)) {
+        if (is_bool($value)) {
             return $this->value === $value;
         }
 
diff --git a/src/ImmutableFloat.php b/src/ImmutableFloat.php
index c987af1..0e23e7f 100644
--- a/src/ImmutableFloat.php
+++ b/src/ImmutableFloat.php
@@ -32,14 +32,14 @@ trait ImmutableFloat
      * @param float $value
      * @return static
      */
-    public static function fromString(float $value): self
+    public static function fromFloat(float $value): self
     {
         return new self($value);
     }
 
     public function __construct(float $value)
     {
-        if(isset($this->value)) {
+        if (isset($this->value)) {
             throw new BadMethodCallException(__METHOD__ . ' called on existing object!');
         }
 
@@ -58,11 +58,11 @@ public function __toString(): string
 
     public function equals($value): bool
     {
-        if(is_object($value) && method_exists($value, 'toFloat')) {
+        if (is_object($value) && method_exists($value, 'toFloat')) {
             return $this->value === $value->toFloat();
         }
 
-        if(is_float($value)) {
+        if (is_float($value)) {
             return $this->value === $value;
         }
 
diff --git a/src/ImmutableInteger.php b/src/ImmutableInteger.php
index c2d20cd..e487632 100644
--- a/src/ImmutableInteger.php
+++ b/src/ImmutableInteger.php
@@ -39,7 +39,7 @@ public static function fromInt(int $value): self
 
     public function __construct(int $value)
     {
-        if(isset($this->value)) {
+        if (isset($this->value)) {
             throw new BadMethodCallException(__METHOD__ . ' called on existing object!');
         }
 
@@ -58,11 +58,11 @@ public function __toString(): string
 
     public function equals($value): bool
     {
-        if(is_object($value) && method_exists($value, 'toInt')) {
+        if (is_object($value) && method_exists($value, 'toInt')) {
             return $this->value === $value->toInt();
         }
 
-        if(is_int($value)) {
+        if (is_int($value)) {
             return $this->value === $value;
         }
 
diff --git a/src/ImmutableList.php b/src/ImmutableList.php
index 8a2f89f..9dbbf2e 100644
--- a/src/ImmutableList.php
+++ b/src/ImmutableList.php
@@ -117,7 +117,7 @@ public function unshift(...$items): self
      */
     public function pop(): self
     {
-        if(count($this->items) === 0) {
+        if (count($this->items) === 0) {
             return $this;
         }
 
@@ -133,7 +133,7 @@ public function pop(): self
      */
     public function shift(): self
     {
-        if(count($this->items) === 0) {
+        if (count($this->items) === 0) {
             return $this;
         }
 
@@ -149,7 +149,7 @@ public function shift(): self
      */
     public function first()
     {
-        if(count($this->items)) {
+        if (count($this->items)) {
             return $this->items[0];
         }
 
@@ -161,7 +161,7 @@ public function first()
      */
     public function last()
     {
-        if(count($this->items)) {
+        if (count($this->items)) {
             return $this->items[count($this->items) - 1];
         }
 
@@ -177,7 +177,7 @@ public function filter(callable $filter): self
         $filteredItems = [];
 
         foreach ($this->items as $item) {
-            if($filter($item)) {
+            if ($filter($item)) {
                 $filteredItems[] = $item;
             }
         }
@@ -189,11 +189,11 @@ public function filter(callable $filter): self
 
     public function equals($other): bool
     {
-        if(is_object($other) && method_exists($other, 'toArray')) {
+        if (is_object($other) && method_exists($other, 'toArray')) {
             return $this->items == $other->toArray();
         }
 
-        if(is_array($other)) {
+        if (is_array($other)) {
             return $this->items == $other;
         }
 
@@ -267,7 +267,7 @@ private static function ensurePropTypeMapIsBuilt(): void
             self::$__propTypeMap = self::buildPropTypeMap();
         }
 
-        if(null === self::$__arrayPropItemTypeMap) {
+        if (null === self::$__arrayPropItemTypeMap) {
             self::$__arrayPropItemTypeMap = self::arrayPropItemTypeMap();
         }
     }
diff --git a/src/ImmutableString.php b/src/ImmutableString.php
index e257dce..4b0c129 100644
--- a/src/ImmutableString.php
+++ b/src/ImmutableString.php
@@ -40,7 +40,7 @@ public static function fromString(string $value): self
 
     public function __construct(string $value)
     {
-        if(isset($this->value)) {
+        if (isset($this->value)) {
             throw new BadMethodCallException(__METHOD__ . ' called on existing object!');
         }
 
@@ -59,11 +59,11 @@ public function __toString(): string
 
     public function equals($value): bool
     {
-        if(is_object($value) && method_exists($value, 'toString')) {
+        if (is_object($value) && method_exists($value, 'toString')) {
             return $this->value === $value->toString();
         }
 
-        if(is_string($value)) {
+        if (is_string($value)) {
             return $this->value === $value;
         }
 
diff --git a/tests/ImmutableBooleanTest.php b/tests/ImmutableBooleanTest.php
index 605cb7a..3c8a748 100644
--- a/tests/ImmutableBooleanTest.php
+++ b/tests/ImmutableBooleanTest.php
@@ -34,7 +34,7 @@ public function it_can_be_created_from_boolean()
     /**
      * @test
      */
-    public function it_equals_other_strings_with_same_value()
+    public function it_equals_other_booleans_with_same_value()
     {
         $access = Access::fromBool(true);
         $other = Access::fromBool(true);
@@ -42,6 +42,7 @@ public function it_equals_other_strings_with_same_value()
         $this->assertTrue($access->equals($other));
         $this->assertTrue($access->equals(true));
         $this->assertFalse($access->equals(false));
+        $this->assertFalse($access->equals('test'));
     }
 
     /**
diff --git a/tests/ImmutableFloatTest.php b/tests/ImmutableFloatTest.php
new file mode 100644
index 0000000..60e0a20
--- /dev/null
+++ b/tests/ImmutableFloatTest.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * This file is part of event-engine/php-types.
+ * (c) 2020 prooph software GmbH <contact@prooph.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+declare(strict_types=1);
+
+namespace EventEngineTest\Type;
+
+use BadMethodCallException;
+use EventEngineTest\Type\Stub\Percentage;
+use PHPUnit\Framework\TestCase;
+
+final class ImmutableFloatTest extends TestCase
+{
+    /**
+     * @test
+     */
+    public function it_can_be_created_from_boolean()
+    {
+        $percentage = Percentage::fromFloat(0.5);
+
+        $this->assertEquals(0.5, $percentage->value);
+        $this->assertEquals(0.5, $percentage->toFloat());
+        $this->assertEquals('0.5', (string)$percentage);
+    }
+
+    /**
+     * @test
+     */
+    public function it_equals_other_floats_with_same_value()
+    {
+        $percentage = Percentage::fromFloat(0.5);
+        $other = Percentage::fromFloat(0.5);
+
+        $this->assertTrue($percentage->equals($other));
+        $this->assertTrue($percentage->equals(0.5));
+        $this->assertFalse($percentage->equals(0.6));
+        $this->assertFalse($percentage->equals('test'));
+    }
+
+    /**
+     * @test
+     */
+    public function it_prevents_double_constructor_calls()
+    {
+        $percentage = new Percentage(0.5);
+
+        $this->expectException(BadMethodCallException::class);
+
+        $percentage->__construct(0.6);
+    }
+}
diff --git a/tests/ImmutableIntegerTest.php b/tests/ImmutableIntegerTest.php
index 29f3908..eff307d 100644
--- a/tests/ImmutableIntegerTest.php
+++ b/tests/ImmutableIntegerTest.php
@@ -40,6 +40,7 @@ public function it_equals_other_integers_with_same_value()
         $this->assertTrue($version->equals($other));
         $this->assertTrue($version->equals(1));
         $this->assertFalse($version->equals(2));
+        $this->assertFalse($version->equals('test'));
     }
 
     /**
diff --git a/tests/ImmutableStringTest.php b/tests/ImmutableStringTest.php
index 8675aea..a23de0e 100644
--- a/tests/ImmutableStringTest.php
+++ b/tests/ImmutableStringTest.php
@@ -39,6 +39,7 @@ public function it_equals_other_strings_with_same_value()
         $this->assertTrue($username->equals($other));
         $this->assertTrue($username->equals('Jane'));
         $this->assertFalse($username->equals('John'));
+        $this->assertFalse($username->equals(123));
     }
 
     /**
diff --git a/tests/Stub/ListWithoutTypeHintedConstructor.php b/tests/Stub/ListWithoutTypeHintedConstructor.php
index 9e5cfbf..451bf5b 100644
--- a/tests/Stub/ListWithoutTypeHintedConstructor.php
+++ b/tests/Stub/ListWithoutTypeHintedConstructor.php
@@ -1,4 +1,11 @@
 <?php
+/**
+ * This file is part of event-engine/php-types.
+ * (c) 2020 prooph software GmbH <contact@prooph.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
 declare(strict_types=1);
 
 namespace EventEngineTest\Type\Stub;
diff --git a/tests/Stub/Percentage.php b/tests/Stub/Percentage.php
new file mode 100644
index 0000000..3de148e
--- /dev/null
+++ b/tests/Stub/Percentage.php
@@ -0,0 +1,18 @@
+<?php
+/**
+ * This file is part of event-engine/php-types.
+ * (c) 2020 prooph software GmbH <contact@prooph.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+declare(strict_types=1);
+
+namespace EventEngineTest\Type\Stub;
+
+use EventEngine\Type\ImmutableFloat;
+
+final class Percentage
+{
+    use ImmutableFloat;
+}