diff --git a/src/Illuminate/Testing/Fluent/Assert.php b/src/Illuminate/Testing/Fluent/Assert.php
new file mode 100644
index 000000000000..bde937a0bf23
--- /dev/null
+++ b/src/Illuminate/Testing/Fluent/Assert.php
@@ -0,0 +1,126 @@
+<?php
+
+namespace Illuminate\Testing\Fluent;
+
+use Closure;
+use Illuminate\Contracts\Support\Arrayable;
+use Illuminate\Support\Arr;
+use Illuminate\Support\Traits\Macroable;
+use Illuminate\Support\Traits\Tappable;
+use Illuminate\Testing\AssertableJsonString;
+use PHPUnit\Framework\Assert as PHPUnit;
+
+class Assert implements Arrayable
+{
+    use Concerns\Has,
+        Concerns\Matching,
+        Concerns\Debugging,
+        Concerns\Interaction,
+        Macroable,
+        Tappable;
+
+    /**
+     * The properties in the current scope.
+     *
+     * @var array
+     */
+    private $props;
+
+    /**
+     * The "dot" path to the current scope.
+     *
+     * @var string|null
+     */
+    private $path;
+
+    /**
+     * Create a new Assert instance.
+     *
+     * @param  array  $props
+     * @param  string|null  $path
+     */
+    protected function __construct(array $props, string $path = null)
+    {
+        $this->path = $path;
+        $this->props = $props;
+    }
+
+    /**
+     * Compose the absolute "dot" path to the given key.
+     *
+     * @param  string  $key
+     * @return string
+     */
+    protected function dotPath(string $key): string
+    {
+        if (is_null($this->path)) {
+            return $key;
+        }
+
+        return implode('.', [$this->path, $key]);
+    }
+
+    /**
+     * Retrieve a prop within the current scope using "dot" notation.
+     *
+     * @param  string|null  $key
+     * @return mixed
+     */
+    protected function prop(string $key = null)
+    {
+        return Arr::get($this->props, $key);
+    }
+
+    /**
+     * Instantiate a new "scope" at the path of the given key.
+     *
+     * @param  string  $key
+     * @param  \Closure  $callback
+     * @return $this
+     */
+    protected function scope(string $key, Closure $callback): self
+    {
+        $props = $this->prop($key);
+        $path = $this->dotPath($key);
+
+        PHPUnit::assertIsArray($props, sprintf('Property [%s] is not scopeable.', $path));
+
+        $scope = new self($props, $path);
+        $callback($scope);
+        $scope->interacted();
+
+        return $this;
+    }
+
+    /**
+     * Create a new instance from an array.
+     *
+     * @param  array  $data
+     * @return static
+     */
+    public static function fromArray(array $data): self
+    {
+        return new self($data);
+    }
+
+    /**
+     * Create a new instance from a AssertableJsonString.
+     *
+     * @param  \Illuminate\Testing\AssertableJsonString  $json
+     * @return static
+     */
+    public static function fromAssertableJsonString(AssertableJsonString $json): self
+    {
+        return self::fromArray($json->json());
+    }
+
+    /**
+     * Get the instance as an array.
+     *
+     * @return array
+     */
+    public function toArray()
+    {
+        return $this->props;
+    }
+}
diff --git a/src/Illuminate/Testing/Fluent/Concerns/Debugging.php b/src/Illuminate/Testing/Fluent/Concerns/Debugging.php
new file mode 100644
index 000000000000..f51d119074ae
--- /dev/null
+++ b/src/Illuminate/Testing/Fluent/Concerns/Debugging.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace Illuminate\Testing\Fluent\Concerns;
+
+trait Debugging
+{
+    /**
+     * Dumps the given props.
+     *
+     * @param  string|null  $prop
+     * @return $this
+     */
+    public function dump(string $prop = null): self
+    {
+        dump($this->prop($prop));
+
+        return $this;
+    }
+
+    /**
+     * Dumps the given props and exits.
+     *
+     * @param  string|null  $prop
+     * @return void
+     */
+    public function dd(string $prop = null): void
+    {
+        dd($this->prop($prop));
+    }
+
+    /**
+     * Retrieve a prop within the current scope using "dot" notation.
+     *
+     * @param  string|null  $key
+     * @return mixed
+     */
+    abstract protected function prop(string $key = null);
+}
diff --git a/src/Illuminate/Testing/Fluent/Concerns/Has.php b/src/Illuminate/Testing/Fluent/Concerns/Has.php
new file mode 100644
index 000000000000..19b9ad9915ca
--- /dev/null
+++ b/src/Illuminate/Testing/Fluent/Concerns/Has.php
@@ -0,0 +1,158 @@
+<?php
+
+namespace Illuminate\Testing\Fluent\Concerns;
+
+use Closure;
+use Illuminate\Support\Arr;
+use PHPUnit\Framework\Assert as PHPUnit;
+
+trait Has
+{
+    /**
+     * Assert that the prop is of the expected size.
+     *
+     * @param  string  $key
+     * @param  int  $length
+     * @return $this
+     */
+    protected function count(string $key, int $length): self
+    {
+        PHPUnit::assertCount(
+            $length,
+            $this->prop($key),
+            sprintf('Property [%s] does not have the expected size.', $this->dotPath($key))
+        );
+
+        return $this;
+    }
+
+    /**
+     * Ensure that the given prop exists.
+     *
+     * @param  string  $key
+     * @param  null  $value
+     * @param  \Closure|null  $scope
+     * @return $this
+     */
+    public function has(string $key, $value = null, Closure $scope = null): self
+    {
+        $prop = $this->prop();
+
+        PHPUnit::assertTrue(
+            Arr::has($prop, $key),
+            sprintf('Property [%s] does not exist.', $this->dotPath($key))
+        );
+
+        $this->interactsWith($key);
+
+        // When all three arguments are provided, this indicates a short-hand
+        // expression that combines both a `count`-assertion, followed by
+        // directly creating a `scope` on the first element.
+        if (is_int($value) && ! is_null($scope)) {
+            $prop = $this->prop($key);
+            $path = $this->dotPath($key);
+
+            PHPUnit::assertTrue($value > 0, sprintf('Cannot scope directly onto the first entry of property [%s] when asserting that it has a size of 0.', $path));
+            PHPUnit::assertIsArray($prop, sprintf('Direct scoping is unsupported for non-array like properties such as [%s].', $path));
+
+            $this->count($key, $value);
+
+            return $this->scope($key.'.'.array_keys($prop)[0], $scope);
+        }
+
+        if (is_callable($value)) {
+            $this->scope($key, $value);
+        } elseif (! is_null($value)) {
+            $this->count($key, $value);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Assert that all of the given props exist.
+     *
+     * @param  array|string $key
+     * @return $this
+     */
+    public function hasAll($key): self
+    {
+        $keys = is_array($key) ? $key : func_get_args();
+
+        foreach ($keys as $prop => $count) {
+            if (is_int($prop)) {
+                $this->has($count);
+            } else {
+                $this->has($prop, $count);
+            }
+        }
+
+        return $this;
+    }
+
+    /**
+     * Assert that none of the given props exist.
+     *
+     * @param  array|string $key
+     * @return $this
+     */
+    public function missingAll($key): self
+    {
+        $keys = is_array($key) ? $key : func_get_args();
+
+        foreach ($keys as $prop) {
+            $this->missing($prop);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Assert that the given prop does not exist.
+     *
+     * @param  string  $key
+     * @return $this
+     */
+    public function missing(string $key): self
+    {
+        PHPUnit::assertNotTrue(
+            Arr::has($this->prop(), $key),
+            sprintf('Property [%s] was found while it was expected to be missing.', $this->dotPath($key))
+        );
+
+        return $this;
+    }
+
+    /**
+     * Compose the absolute "dot" path to the given key.
+     *
+     * @param  string  $key
+     * @return string
+     */
+    abstract protected function dotPath(string $key): string;
+
+    /**
+     * Marks the property as interacted.
+     *
+     * @param  string  $key
+     * @return void
+     */
+    abstract protected function interactsWith(string $key): void;
+
+    /**
+     * Retrieve a prop within the current scope using "dot" notation.
+     *
+     * @param  string|null  $key
+     * @return mixed
+     */
+    abstract protected function prop(string $key = null);
+
+    /**
+     * Instantiate a new "scope" at the path of the given key.
+     *
+     * @param  string  $key
+     * @param  \Closure  $callback
+     * @return $this
+     */
+    abstract protected function scope(string $key, Closure $callback);
+}
diff --git a/src/Illuminate/Testing/Fluent/Concerns/Interaction.php b/src/Illuminate/Testing/Fluent/Concerns/Interaction.php
new file mode 100644
index 000000000000..15e7e9508f55
--- /dev/null
+++ b/src/Illuminate/Testing/Fluent/Concerns/Interaction.php
@@ -0,0 +1,67 @@
+<?php
+
+namespace Illuminate\Testing\Fluent\Concerns;
+
+use Illuminate\Support\Str;
+use PHPUnit\Framework\Assert as PHPUnit;
+
+trait Interaction
+{
+    /**
+     * The list of interacted properties.
+     *
+     * @var array
+     */
+    protected $interacted = [];
+
+    /**
+     * Marks the property as interacted.
+     *
+     * @param  string  $key
+     * @return void
+     */
+    protected function interactsWith(string $key): void
+    {
+        $prop = Str::before($key, '.');
+
+        if (! in_array($prop, $this->interacted, true)) {
+            $this->interacted[] = $prop;
+        }
+    }
+
+    /**
+     * Asserts that all properties have been interacted with.
+     *
+     * @return void
+     */
+    public function interacted(): void
+    {
+        PHPUnit::assertSame(
+            [],
+            array_diff(array_keys($this->prop()), $this->interacted),
+            $this->path
+                ? sprintf('Unexpected properties were found in scope [%s].', $this->path)
+                : 'Unexpected properties were found on the root level.'
+        );
+    }
+
+    /**
+     * Disables the interaction check.
+     *
+     * @return $this
+     */
+    public function etc(): self
+    {
+        $this->interacted = array_keys($this->prop());
+
+        return $this;
+    }
+
+    /**
+     * Retrieve a prop within the current scope using "dot" notation.
+     *
+     * @param  string|null  $key
+     * @return mixed
+     */
+    abstract protected function prop(string $key = null);
+}
diff --git a/src/Illuminate/Testing/Fluent/Concerns/Matching.php b/src/Illuminate/Testing/Fluent/Concerns/Matching.php
new file mode 100644
index 000000000000..3cf1f82c471c
--- /dev/null
+++ b/src/Illuminate/Testing/Fluent/Concerns/Matching.php
@@ -0,0 +1,109 @@
+<?php
+
+namespace Illuminate\Testing\Fluent\Concerns;
+
+use Closure;
+use Illuminate\Contracts\Support\Arrayable;
+use Illuminate\Support\Collection;
+use PHPUnit\Framework\Assert as PHPUnit;
+
+trait Matching
+{
+    /**
+     * Asserts that the property matches the expected value.
+     *
+     * @param  string  $key
+     * @param  mixed|\Closure  $expected
+     * @return $this
+     */
+    public function where(string $key, $expected): self
+    {
+        $this->has($key);
+
+        $actual = $this->prop($key);
+
+        if ($expected instanceof Closure) {
+            PHPUnit::assertTrue(
+                $expected(is_array($actual) ? Collection::make($actual) : $actual),
+                sprintf('Property [%s] was marked as invalid using a closure.', $this->dotPath($key))
+            );
+
+            return $this;
+        }
+
+        if ($expected instanceof Arrayable) {
+            $expected = $expected->toArray();
+        }
+
+        $this->ensureSorted($expected);
+        $this->ensureSorted($actual);
+
+        PHPUnit::assertSame(
+            $expected,
+            $actual,
+            sprintf('Property [%s] does not match the expected value.', $this->dotPath($key))
+        );
+
+        return $this;
+    }
+
+    /**
+     * Asserts that all properties match their expected values.
+     *
+     * @param  array  $bindings
+     * @return $this
+     */
+    public function whereAll(array $bindings): self
+    {
+        foreach ($bindings as $key => $value) {
+            $this->where($key, $value);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Ensures that all properties are sorted the same way, recursively.
+     *
+     * @param  mixed  $value
+     * @return void
+     */
+    protected function ensureSorted(&$value): void
+    {
+        if (! is_array($value)) {
+            return;
+        }
+
+        foreach ($value as &$arg) {
+            $this->ensureSorted($arg);
+        }
+
+        ksort($value);
+    }
+
+    /**
+     * Compose the absolute "dot" path to the given key.
+     *
+     * @param  string  $key
+     * @return string
+     */
+    abstract protected function dotPath(string $key): string;
+
+    /**
+     * Ensure that the given prop exists.
+     *
+     * @param  string  $key
+     * @param  null  $value
+     * @param  \Closure|null  $scope
+     * @return $this
+     */
+    abstract public function has(string $key, $value = null, Closure $scope = null);
+
+    /**
+     * Retrieve a prop within the current scope using "dot" notation.
+     *
+     * @param  string|null  $key
+     * @return mixed
+     */
+    abstract protected function prop(string $key = null);
+}
diff --git a/src/Illuminate/Testing/TestResponse.php b/src/Illuminate/Testing/TestResponse.php
index 1bfc75285518..eb983f464a6d 100644
--- a/src/Illuminate/Testing/TestResponse.php
+++ b/src/Illuminate/Testing/TestResponse.php
@@ -14,6 +14,7 @@
 use Illuminate\Support\Traits\Tappable;
 use Illuminate\Testing\Assert as PHPUnit;
 use Illuminate\Testing\Constraints\SeeInOrder;
+use Illuminate\Testing\Fluent\Assert as FluentAssert;
 use LogicException;
 use Symfony\Component\HttpFoundation\StreamedResponse;
 
@@ -507,13 +508,25 @@ public function assertDontSeeText($value, $escape = true)
     /**
      * Assert that the response is a superset of the given JSON.
      *
-     * @param  array  $data
+     * @param  array|callable  $value
      * @param  bool  $strict
      * @return $this
      */
-    public function assertJson(array $data, $strict = false)
+    public function assertJson($value, $strict = false)
     {
-        $this->decodeResponseJson()->assertSubset($data, $strict);
+        $json = $this->decodeResponseJson();
+
+        if (is_array($value)) {
+            $json->assertSubset($value, $strict);
+        } else {
+            $assert = FluentAssert::fromAssertableJsonString($json);
+
+            $value($assert);
+
+            if ($strict) {
+                $assert->interacted();
+            }
+        }
 
         return $this;
     }
diff --git a/tests/Testing/Fluent/AssertTest.php b/tests/Testing/Fluent/AssertTest.php
new file mode 100644
index 000000000000..f02e366f40a0
--- /dev/null
+++ b/tests/Testing/Fluent/AssertTest.php
@@ -0,0 +1,688 @@
+<?php
+
+namespace Illuminate\Tests\Testing\Fluent;
+
+use Illuminate\Support\Collection;
+use Illuminate\Testing\Fluent\Assert;
+use Illuminate\Tests\Testing\Stubs\ArrayableStubObject;
+use PHPUnit\Framework\AssertionFailedError;
+use PHPUnit\Framework\TestCase;
+use RuntimeException;
+use TypeError;
+
+class AssertTest extends TestCase
+{
+    public function testAssertHas()
+    {
+        $assert = Assert::fromArray([
+            'prop' => 'value',
+        ]);
+
+        $assert->has('prop');
+    }
+
+    public function testAssertHasFailsWhenPropMissing()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 'value',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [prop] does not exist.');
+
+        $assert->has('prop');
+    }
+
+    public function testAssertHasNestedProp()
+    {
+        $assert = Assert::fromArray([
+            'example' => [
+                'nested' => 'nested-value',
+            ],
+        ]);
+
+        $assert->has('example.nested');
+    }
+
+    public function testAssertHasFailsWhenNestedPropMissing()
+    {
+        $assert = Assert::fromArray([
+            'example' => [
+                'nested' => 'nested-value',
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [example.another] does not exist.');
+
+        $assert->has('example.another');
+    }
+
+    public function testAssertCountItemsInProp()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'example',
+                'prop' => 'value',
+            ],
+        ]);
+
+        $assert->has('bar', 2);
+    }
+
+    public function testAssertCountFailsWhenAmountOfItemsDoesNotMatch()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'example',
+                'prop' => 'value',
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [bar] does not have the expected size.');
+
+        $assert->has('bar', 1);
+    }
+
+    public function testAssertCountFailsWhenPropMissing()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'example',
+                'prop' => 'value',
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [baz] does not exist.');
+
+        $assert->has('baz', 1);
+    }
+
+    public function testAssertHasFailsWhenSecondArgumentUnsupportedType()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 'baz',
+        ]);
+
+        $this->expectException(TypeError::class);
+
+        $assert->has('bar', 'invalid');
+    }
+
+    public function testAssertMissing()
+    {
+        $assert = Assert::fromArray([
+            'foo' => [
+                'bar' => true,
+            ],
+        ]);
+
+        $assert->missing('foo.baz');
+    }
+
+    public function testAssertMissingFailsWhenPropExists()
+    {
+        $assert = Assert::fromArray([
+            'prop' => 'value',
+            'foo' => [
+                'bar' => true,
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [foo.bar] was found while it was expected to be missing.');
+
+        $assert->missing('foo.bar');
+    }
+
+    public function testAssertMissingAll()
+    {
+        $assert = Assert::fromArray([
+            'baz' => 'foo',
+        ]);
+
+        $assert->missingAll([
+            'foo',
+            'bar',
+        ]);
+    }
+
+    public function testAssertMissingAllFailsWhenAtLeastOnePropExists()
+    {
+        $assert = Assert::fromArray([
+            'baz' => 'foo',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [baz] was found while it was expected to be missing.');
+
+        $assert->missingAll([
+            'bar',
+            'baz',
+        ]);
+    }
+
+    public function testAssertMissingAllAcceptsMultipleArgumentsInsteadOfArray()
+    {
+        $assert = Assert::fromArray([
+            'baz' => 'foo',
+        ]);
+
+        $assert->missingAll('foo', 'bar');
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [baz] was found while it was expected to be missing.');
+
+        $assert->missingAll('bar', 'baz');
+    }
+
+    public function testAssertWhereMatchesValue()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 'value',
+        ]);
+
+        $assert->where('bar', 'value');
+    }
+
+    public function testAssertWhereFailsWhenDoesNotMatchValue()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 'value',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [bar] does not match the expected value.');
+
+        $assert->where('bar', 'invalid');
+    }
+
+    public function testAssertWhereFailsWhenMissing()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 'value',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [baz] does not exist.');
+
+        $assert->where('baz', 'invalid');
+    }
+
+    public function testAssertWhereFailsWhenMachingLoosely()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 1,
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [bar] does not match the expected value.');
+
+        $assert->where('bar', true);
+    }
+
+    public function testAssertWhereUsingClosure()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 'baz',
+        ]);
+
+        $assert->where('bar', function ($value) {
+            return $value === 'baz';
+        });
+    }
+
+    public function testAssertWhereFailsWhenDoesNotMatchValueUsingClosure()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 'baz',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [bar] was marked as invalid using a closure.');
+
+        $assert->where('bar', function ($value) {
+            return $value === 'invalid';
+        });
+    }
+
+    public function testAssertWhereClosureArrayValuesAreAutomaticallyCastedToCollections()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'foo',
+                'example' => 'value',
+            ],
+        ]);
+
+        $assert->where('bar', function ($value) {
+            $this->assertInstanceOf(Collection::class, $value);
+
+            return $value->count() === 2;
+        });
+    }
+
+    public function testAssertWhereMatchesValueUsingArrayable()
+    {
+        $stub = ArrayableStubObject::make(['foo' => 'bar']);
+
+        $assert = Assert::fromArray([
+            'bar' => $stub->toArray(),
+        ]);
+
+        $assert->where('bar', $stub);
+    }
+
+    public function testAssertWhereMatchesValueUsingArrayableWhenSortedDifferently()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'foo',
+                'example' => 'value',
+            ],
+        ]);
+
+        $assert->where('bar', function ($value) {
+            $this->assertInstanceOf(Collection::class, $value);
+
+            return $value->count() === 2;
+        });
+    }
+
+    public function testAssertWhereFailsWhenDoesNotMatchValueUsingArrayable()
+    {
+        $assert = Assert::fromArray([
+            'bar' => ['id' => 1, 'name' => 'Example'],
+            'baz' => [
+                'id' => 1,
+                'name' => 'Taylor Otwell',
+                'email' => 'taylor@laravel.com',
+                'email_verified_at' => '2021-01-22T10:34:42.000000Z',
+                'created_at' => '2021-01-22T10:34:42.000000Z',
+                'updated_at' => '2021-01-22T10:34:42.000000Z',
+            ],
+        ]);
+
+        $assert
+            ->where('bar', ArrayableStubObject::make(['name' => 'Example', 'id' => 1]))
+            ->where('baz', [
+                'name' => 'Taylor Otwell',
+                'email' => 'taylor@laravel.com',
+                'id' => 1,
+                'email_verified_at' => '2021-01-22T10:34:42.000000Z',
+                'updated_at' => '2021-01-22T10:34:42.000000Z',
+                'created_at' => '2021-01-22T10:34:42.000000Z',
+            ]);
+    }
+
+    public function testAssertNestedWhereMatchesValue()
+    {
+        $assert = Assert::fromArray([
+            'example' => [
+                'nested' => 'nested-value',
+            ],
+        ]);
+
+        $assert->where('example.nested', 'nested-value');
+    }
+
+    public function testAssertNestedWhereFailsWhenDoesNotMatchValue()
+    {
+        $assert = Assert::fromArray([
+            'example' => [
+                'nested' => 'nested-value',
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [example.nested] does not match the expected value.');
+
+        $assert->where('example.nested', 'another-value');
+    }
+
+    public function testScope()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'example',
+                'prop' => 'value',
+            ],
+        ]);
+
+        $called = false;
+        $assert->has('bar', function (Assert $assert) use (&$called) {
+            $called = true;
+            $assert
+                ->where('baz', 'example')
+                ->where('prop', 'value');
+        });
+
+        $this->assertTrue($called, 'The scoped query was never actually called.');
+    }
+
+    public function testScopeFailsWhenPropMissing()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'example',
+                'prop' => 'value',
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [baz] does not exist.');
+
+        $assert->has('baz', function (Assert $item) {
+            $item->where('baz', 'example');
+        });
+    }
+
+    public function testScopeFailsWhenPropSingleValue()
+    {
+        $assert = Assert::fromArray([
+            'bar' => 'value',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [bar] is not scopeable.');
+
+        $assert->has('bar', function (Assert $item) {
+            //
+        });
+    }
+
+    public function testScopeShorthand()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                ['key' => 'first'],
+                ['key' => 'second'],
+            ],
+        ]);
+
+        $called = false;
+        $assert->has('bar', 2, function (Assert $item) use (&$called) {
+            $item->where('key', 'first');
+            $called = true;
+        });
+
+        $this->assertTrue($called, 'The scoped query was never actually called.');
+    }
+
+    public function testScopeShorthandFailsWhenAssertingZeroItems()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                ['key' => 'first'],
+                ['key' => 'second'],
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Cannot scope directly onto the first entry of property [bar] when asserting that it has a size of 0.');
+
+        $assert->has('bar', 0, function (Assert $item) {
+            $item->where('key', 'first');
+        });
+    }
+
+    public function testScopeShorthandFailsWhenAmountOfItemsDoesNotMatch()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                ['key' => 'first'],
+                ['key' => 'second'],
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [bar] does not have the expected size.');
+
+        $assert->has('bar', 1, function (Assert $item) {
+            $item->where('key', 'first');
+        });
+    }
+
+    public function testFailsWhenNotInteractingWithAllPropsInScope()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'example',
+                'prop' => 'value',
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Unexpected properties were found in scope [bar].');
+
+        $assert->has('bar', function (Assert $item) {
+            $item->where('baz', 'example');
+        });
+    }
+
+    public function testDisableInteractionCheckForCurrentScope()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'example',
+                'prop' => 'value',
+            ],
+        ]);
+
+        $assert->has('bar', function (Assert $item) {
+            $item->etc();
+        });
+    }
+
+    public function testCannotDisableInteractionCheckForDifferentScopes()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => [
+                    'foo' => 'bar',
+                    'example' => 'value',
+                ],
+                'prop' => 'value',
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Unexpected properties were found in scope [bar.baz].');
+
+        $assert->has('bar', function (Assert $item) {
+            $item
+                ->etc()
+                ->has('baz', function (Assert $item) {
+                    //
+                });
+        });
+    }
+
+    public function testTopLevelPropInteractionDisabledByDefault()
+    {
+        $assert = Assert::fromArray([
+            'foo' => 'bar',
+            'bar' => 'baz',
+        ]);
+
+        $assert->has('foo');
+    }
+
+    public function testTopLevelInteractionEnabledWhenInteractedFlagSet()
+    {
+        $assert = Assert::fromArray([
+            'foo' => 'bar',
+            'bar' => 'baz',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Unexpected properties were found on the root level.');
+
+        $assert
+            ->has('foo')
+            ->interacted();
+    }
+
+    public function testAssertWhereAllMatchesValues()
+    {
+        $assert = Assert::fromArray([
+            'foo' => [
+                'bar' => 'value',
+                'example' => ['hello' => 'world'],
+            ],
+            'baz' => 'another',
+        ]);
+
+        $assert->whereAll([
+            'foo.bar' => 'value',
+            'foo.example' => ArrayableStubObject::make(['hello' => 'world']),
+            'baz' => function ($value) {
+                return $value === 'another';
+            },
+        ]);
+    }
+
+    public function testAssertWhereAllFailsWhenAtLeastOnePropDoesNotMatchValue()
+    {
+        $assert = Assert::fromArray([
+            'foo' => 'bar',
+            'baz' => 'example',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [baz] was marked as invalid using a closure.');
+
+        $assert->whereAll([
+            'foo' => 'bar',
+            'baz' => function ($value) {
+                return $value === 'foo';
+            },
+        ]);
+    }
+
+    public function testAssertHasAll()
+    {
+        $assert = Assert::fromArray([
+            'foo' => [
+                'bar' => 'value',
+                'example' => ['hello' => 'world'],
+            ],
+            'baz' => 'another',
+        ]);
+
+        $assert->hasAll([
+            'foo.bar',
+            'foo.example',
+            'baz',
+        ]);
+    }
+
+    public function testAssertHasAllFailsWhenAtLeastOnePropMissing()
+    {
+        $assert = Assert::fromArray([
+            'foo' => [
+                'bar' => 'value',
+                'example' => ['hello' => 'world'],
+            ],
+            'baz' => 'another',
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [foo.baz] does not exist.');
+
+        $assert->hasAll([
+            'foo.bar',
+            'foo.baz',
+            'baz',
+        ]);
+    }
+
+    public function testAssertHasAllAcceptsMultipleArgumentsInsteadOfArray()
+    {
+        $assert = Assert::fromArray([
+            'foo' => [
+                'bar' => 'value',
+                'example' => ['hello' => 'world'],
+            ],
+            'baz' => 'another',
+        ]);
+
+        $assert->hasAll('foo.bar', 'foo.example', 'baz');
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [foo.baz] does not exist.');
+
+        $assert->hasAll('foo.bar', 'foo.baz', 'baz');
+    }
+
+    public function testAssertCountMultipleProps()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'key' => 'value',
+                'prop' => 'example',
+            ],
+            'baz' => [
+                'another' => 'value',
+            ],
+        ]);
+
+        $assert->hasAll([
+            'bar' => 2,
+            'baz' => 1,
+        ]);
+    }
+
+    public function testAssertCountMultiplePropsFailsWhenPropMissing()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'key' => 'value',
+                'prop' => 'example',
+            ],
+        ]);
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Property [baz] does not exist.');
+
+        $assert->hasAll([
+            'bar' => 2,
+            'baz' => 1,
+        ]);
+    }
+
+    public function testMacroable()
+    {
+        Assert::macro('myCustomMacro', function () {
+            throw new RuntimeException('My Custom Macro was called!');
+        });
+
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('My Custom Macro was called!');
+
+        $assert = Assert::fromArray(['foo' => 'bar']);
+        $assert->myCustomMacro();
+    }
+
+    public function testTappable()
+    {
+        $assert = Assert::fromArray([
+            'bar' => [
+                'baz' => 'example',
+                'prop' => 'value',
+            ],
+        ]);
+
+        $called = false;
+        $assert->has('bar', function (Assert $assert) use (&$called) {
+            $assert->etc();
+            $assert->tap(function (Assert $assert) use (&$called) {
+                $called = true;
+            });
+        });
+
+        $this->assertTrue($called, 'The scoped query was never actually called.');
+    }
+}
diff --git a/tests/Testing/Stubs/ArrayableStubObject.php b/tests/Testing/Stubs/ArrayableStubObject.php
new file mode 100644
index 000000000000..021440e0b287
--- /dev/null
+++ b/tests/Testing/Stubs/ArrayableStubObject.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace Illuminate\Tests\Testing\Stubs;
+
+use Illuminate\Contracts\Support\Arrayable;
+
+class ArrayableStubObject implements Arrayable
+{
+    protected $data;
+
+    public function __construct($data = [])
+    {
+        $this->data = $data;
+    }
+
+    public static function make($data = [])
+    {
+        return new self($data);
+    }
+
+    public function toArray()
+    {
+        return $this->data;
+    }
+}
diff --git a/tests/Testing/TestResponseTest.php b/tests/Testing/TestResponseTest.php
index 42d16e72d3fa..055519925cb9 100644
--- a/tests/Testing/TestResponseTest.php
+++ b/tests/Testing/TestResponseTest.php
@@ -9,6 +9,7 @@
 use Illuminate\Encryption\Encrypter;
 use Illuminate\Filesystem\Filesystem;
 use Illuminate\Http\Response;
+use Illuminate\Testing\Fluent\Assert;
 use Illuminate\Testing\TestResponse;
 use JsonSerializable;
 use Mockery as m;
@@ -577,6 +578,27 @@ public function testAssertJsonWithNull()
         $response->assertJson($resource->jsonSerialize());
     }
 
+    public function testAssertJsonWithFluent()
+    {
+        $response = TestResponse::fromBaseResponse(new Response(new JsonSerializableSingleResourceStub));
+
+        $response->assertJson(function (Assert $json) {
+            $json->where('0.foo', 'foo 0');
+        });
+    }
+
+    public function testAssertJsonWithFluentStrict()
+    {
+        $response = TestResponse::fromBaseResponse(new Response(new JsonSerializableSingleResourceStub));
+
+        $this->expectException(AssertionFailedError::class);
+        $this->expectExceptionMessage('Unexpected properties were found on the root level.');
+
+        $response->assertJson(function (Assert $json) {
+            $json->where('0.foo', 'foo 0');
+        }, true);
+    }
+
     public function testAssertSimilarJsonWithMixed()
     {
         $response = TestResponse::fromBaseResponse(new Response(new JsonSerializableMixedResourcesStub));