# Dependencies { #dependencies }

**FastAPI** has a very powerful but intuitive **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection" { #what-is-dependency-injection }

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

It declares an optional query parameter `q` as a `str`, and then it just returns it.

This is quite simple (not very useful), but will help us focus on how the sub-dependencies work.

## Second dependency, "dependable" and "dependant" { #second-dependency-dependable-and-dependant }

That's what all the systems with "login with Facebook, Google, X (Twitter), GitHub" use underneath.

### OAuth 1 { #oauth-1 }

There was an OAuth 1, which is very different from OAuth2, and more complex, as it included direct specifications on how to encrypt the communication.

It is not very popular or used nowadays.

OAuth2 doesn't specify how to encrypt the communication, it expects you to have your application served with HTTPS.

/// tip

# GraphQL { #graphql }

As **FastAPI** is based on the **ASGI** standard, it's very easy to integrate any **GraphQL** library also compatible with ASGI.

You can combine normal FastAPI *path operations* with GraphQL on the same application.

/// tip

**GraphQL** solves some very specific use cases.

It has **advantages** and **disadvantages** when compared to common **web APIs**.

Package: fess
Version: [[version]]
Architecture: all
Maintainer: Fess Team
Depends: libc6, adduser
Section: web
Priority: optional
Homepage: https://github.com/codelibs/fess
Description: Enterprise Search Server: Fess

Because this code is executed before the application **starts** taking requests, and right after it **finishes** handling requests, it covers the whole application **lifespan** (the word "lifespan" will be important in a second 😉).

- OkHttp is a small and light dependency.  Don't introduce new dependencies or major new functionality.
- OkHttp targets the intersection of RFC correct *and* widely implemented.  Incorrect implementations that are very widely implemented e.g. a bug in Apache, Nginx, Google, Firefox should also be handled.

Before your code can be accepted into the project you must also sign the
[Individual Contributor License Agreement (CLA)][1].

        assertEquals(8, encrypted.length);
        assertNotEquals(new String(plaintext), new String(encrypted));
    }

    @ParameterizedTest
    @ValueSource(strings = { "", "a", "short", "medium length text", "very long text that exceeds typical block sizes" })
    @DisplayName("Should handle various input sizes for hashing")
    void testHashVariousInputSizes(String input) {
        // Given
        byte[] data = input.getBytes();

        assertEquals(message, exception.getMessage());
    }

    public void test_veryLongMessage() {
        // Test with very long message
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 1000; i++) {
            sb.append("Very long error message line ").append(i).append(". ");
        }
        String longMessage = sb.toString();

# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
# Release jobs are very basic. They don't use any caching or RBE,
# but they do upload logs to resultstore.
# IMPORTANT: trailing slash is required on GCS URIs, as it tells gcloud to
# pretend the path is a directory.
TFCI_ARTIFACT_FINAL_GCS_ENABLE=1