}

func TestS2CompressReader(t *testing.T) {
	tests := []struct {
		name    string
		data    []byte
		wantIdx bool
	}{
		{name: "empty", data: nil},
		{name: "small", data: []byte("hello, world!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!")},
		{name: "large", data: bytes.Repeat([]byte("hello, world"), 1000000), wantIdx: true},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {

			}
			if missingAll > 0 {
				out += ".incomplete"
				fmt.Println(missingAll, "bytes missing.")
			} else {
				if wantMD5 != "" {
					sum := md5.Sum(combined)
					gotMD5 := hex.EncodeToString(sum[:])
					if gotMD5 != wantMD5 {
						fmt.Println("MD5 mismatch. Expected", wantMD5, "got", gotMD5)
						out += ".mismatch"
					} else {
						fmt.Println("MD5 verified.")

		{"000000000000bogus", 0, "invalid byte in chunk length"},
		{"00000000000000000", 0, "http chunk length too large"}, // could accept if we wanted
		{"10000000000000000", 0, "http chunk length too large"},
		{"00000000000000001", 0, "http chunk length too large"}, // could accept if we wanted
	}
	for i := uint64(0); i <= 1234; i++ {
		tests = append(tests, testCase{in: fmt.Sprintf("%x", i), want: i})
	}
	for _, tt := range tests {

## Design { #design }

Then I spent some time designing the developer "API" I wanted to have as a user (as a developer using FastAPI).

I tested several ideas in the most popular Python editors: PyCharm, VS Code, Jedi based editors.

...but continue reading below to see how to overcome that.

## Return Type and Data Filtering { #return-type-and-data-filtering }

Let's continue from the previous example. We wanted to **annotate the function with one type**, but we wanted to be able to return from the function something that actually includes **more data**.

---

"_Honestly, what you've built looks super solid and polished. In many ways, it's what I wanted **Hug** to be - it's really inspiring to see someone build that._"

This decoupling of parts, and being a "microframework" that could be extended to cover exactly what is needed was a key feature that I wanted to keep.

Given the simplicity of Flask, it seemed like a good match for building APIs. The next thing to find was a "Django REST Framework" for Flask.

/// check | Inspired **FastAPI** to

---

"_Honestly, what you've built looks super solid and polished. In many ways, it's what I wanted **Hug** to be - it's really inspiring to see someone build that._"

You can check it at <a href="http://127.0.0.1:9999/api/v1/docs" class="external-link" target="_blank">http://127.0.0.1:9999/api/v1/docs</a>:

<img src="/img/tutorial/behind-a-proxy/image02.png">

Right as we wanted it. ✔️

This is because FastAPI uses this `root_path` to create the default `server` in OpenAPI with the URL provided by `root_path`.

## Additional servers { #additional-servers }

/// warning

---

"_Honestly, what you've built looks super solid and polished. In many ways, it's what I wanted **Hug** to be - it's really inspiring to see someone build that._"