RFC: Extending the CLI by loading externally-defined functions

[cleopatrio]

Extensions file

// file: extensions/0001.go
package mock_http_extensions

import (
	"fmt"
	"net/http"
	"time"
)

func RequestTransformerFunc(*http.Request) *http.Request { return nil }

func ResponseTransformerFunc(*http.Response) *http.Response { return nil }

func ResponsePassesValidationFunc(req *http.Request, res *http.Response, tests struct {
	HTTP *struct {
		Status  *int
		Headers map[string][]string
		Body    any
	}
	Duration *time.Duration
}) bool {
        var isOk bool

	status := Unwrap[int](tests.HTTP.Status, -100)

	if status != res.StatusCode {
		fmt.Printf("ERROR: expected status %v, but got %v\n", status, res.StatusCode)
	}

	// TODO: Test body and headers

	return isOk
}

func Unwrap[T any](optional *T, d T) T {
	if optional == nil {
		return d
	}
	return *optional
}

Env

# 1 - fatal
# 2 - error
# 3 - warn
# 4 - info
# 5 - debug
LOG_LEVEL=5
PLUGINS_FILEPATH=./extensions/0001.go

Execution log

go run . http -o yaml -f ./examples/0001.yaml
WARN[0000] Loaded extension: ResponsePassesValidationFunc 0x1044dc5a0
WARN[0000] Loaded extension: RequestTransformerFunc 0x1044dc5a0
WARN[0000] Loaded extension: ResponseTransformerFunc 0x1044dc5a0
DEBU[0000] schema.LoadSchema
DEBU[0000] schema.Execute
DEBU[0000] schema.Consume
DEBU[0000] schema.Send
DEBU[0000] schema.(*Request).ParseURL
DEBU[0000] schema.(*Request).ParseURL https://api.datamuse.com/words?ml=ocean
DEBU[0000] schema.(*Request).HeaderMap
DEBU[0001] schema.Send request sent...
DEBU[0001] Response for: Datamuse - words related to `ocean`
DEBU[0001] schema.(*Request).ParseURL
DEBU[0001] schema.(*Request).ParseURL https://api.datamuse.com/words?ml=ocean
DEBU[0001] schema.BodyMarshalFunc application/json
WARN[0001] Running code for: ResponsePassesValidationFunc
WARN[0001] Running tests for: Datamuse - words related to `ocean`

ERROR: expected status 400, but got 200

For more details, check out the extensions directory and how it is used in main.go