# How To - Recetas

Aquí verás diferentes recetas o guías de "cómo hacer" para **varios temas**.

La mayoría de estas ideas serían más o menos **independientes**, y en la mayoría de los casos solo deberías estudiarlas si aplican directamente a **tu proyecto**.

Si algo parece interesante y útil para tu proyecto, adelante y revísalo, pero de lo contrario, probablemente puedas simplemente omitirlas.

/// tip | Consejo

		keyval := strings.SplitN(query, "=", 2)
		if len(keyval) != 2 {
			return ErrInvalidQueryParams
		}
		switch keyval[0] {
		case xhttp.AmzAccessKeyID:
			accessKey = keyval[1]
		case xhttp.AmzSignatureV2:
			gotSignature = keyval[1]
		case xhttp.Expires:
			expires = keyval[1]
		default:
			filteredQueries = append(filteredQueries, query)
		}
	}

	// Invalid values returns error.

    private policy_handle mockHandle;

    @BeforeEach
    void setUp() {
        // Create a mock policy_handle for each test
        mockHandle = mock(policy_handle.class);
    }

    /**
     * Test case for the {@link MsrpcLsarClose#MsrpcLsarClose(policy_handle)} constructor.
     * Verifies that the handle, ptype, and flags are correctly initialized.
     */
    @Test
    void testConstructor() {

								},
							},
						},
					},
				},
			}, clause.From{}},
			"SELECT `age` = ? as name FROM `users`",
			[]interface{}{18},
		},
	}

	for idx, result := range results {
		t.Run(fmt.Sprintf("case #%v", idx), func(t *testing.T) {
			checkBuildClauses(t, result.Clauses, result.Result, result.Vars)
		})
	}

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

## Read the Tutorial first { #read-the-tutorial-first }

#!/usr/bin/env bash
# Copyright 2023 The Go Authors. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

case "$GOWASIRUNTIME" in
	"wasmedge")
		exec wasmedge --dir=/ --env PWD="$PWD" --env PATH="$PATH" ${GOWASIRUNTIMEARGS:-} "$1" "${@:2}"
		;;
	"wasmer")
		exec wasmer run --dir=/ --env PWD="$PWD" --env PATH="$PATH" ${GOWASIRUNTIMEARGS:-} "$1" -- "${@:2}"
		;;
	"wazero")

    @Throws(IOException::class)
    fun parse(responseHeaders: Headers): WebSocketExtensions {
      // Note that this code does case-insensitive comparisons, even though the spec doesn't specify
      // whether extension tokens and parameters are case-insensitive or not.

      var compressionEnabled = false
      var clientMaxWindowBits: Int? = null
      var clientNoContextTakeover = false

		r.Header = test.Header
		r.URL = test.URL

		h := setRequestValidityMiddleware(okHandler)
		h.ServeHTTP(w, r)

		switch {
		case test.ShouldFail && w.Code == http.StatusOK:
			t.Errorf("Test %d: should fail but status code is HTTP %d", i, w.Code)
		case !test.ShouldFail && w.Code != http.StatusOK:
			t.Errorf("Test %d: should not fail but status code is HTTP %d and not 200 OK", i, w.Code)
		}
	}
}

Create a function to be run as the background task.

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

// `run_metadata`) are valid.
//
//    - `run_options` may be NULL, in which case it will be ignored; or
//      non-NULL, in which case it must point to a `TF_Buffer` containing the
//      serialized representation of a `RunOptions` protocol buffer.
//    - `run_metadata` may be NULL, in which case it will be ignored; or
//      non-NULL, in which case it must point to an empty, freshly allocated