plugin

plugin

When you need to do some dynamic calculations or custom logic processing in testcases, you need to use the plugin function mechanism.

HttpRunner+ supports both hashicorp/plugin and go plugin to create and call custom functions.

hashicorp/plugin

It is recommended to use hashicorp/plugin in most cases.

create plugin functions

Firstly, you need to define your plugin functions. The functions can be very flexible, only the following restrictions should be complied with.

• function should return at most one value and one error.
• Register() and Serve() must be called to register plugin functions and start a plugin server process in main().

Here is some plugin functions as example.

package main

import (
	"fmt"

	"github.com/httprunner/hrp/plugin"
)

func SumTwoInt(a, b int) int {
	return a + b
}

func SumInts(args ...int) int {
	var sum int
	for _, arg := range args {
		sum += arg
	}
	return sum
}

func Sum(args ...interface{}) (interface{}, error) {
	var sum float64
	for _, arg := range args {
		switch v := arg.(type) {
		case int:
			sum += float64(v)
		case float64:
			sum += v
		default:
			return nil, fmt.Errorf("unexpected type: %T", arg)
		}
	}
	return sum, nil
}

func main() {
	plugin.Register("sum_ints", SumInts)
	plugin.Register("sum_two_int", SumTwoInt)
	plugin.Register("sum", Sum)
	plugin.Serve()
}

You can get more examples at examples/plugin/

build plugin

Secondly, you can build your hashicorp plugin to binary file debugtalk.bin. The name of debugtalk.bin is by convention and should not be changed.

$ go build -o examples/debugtalk.bin examples/plugin/hashicorp.go examples/plugin/debugtalk.go

It is recommended to place the debugtalk.bin file in your project root folder, or you can put it in the parent folder of the target testcase file. HttpRunner+ will search debugtalk.bin upward recursively until current working directory or system root dir.

use plugin functions

Then, you can call your defined plugin function in your YAML/JSON testcase at any position.

{
    "name": "get with params",
    "variables": {
        "a": "${sum_two_int(1,6)}",
        "b": "${sum_ints(1,2,3)}",
        "c": "${sum(1, 2.3, 4)}",
    },
    "request": {
        "method": "GET",
        "url": "/get",
        "params": {
            "foo1": "$c",
            "foo2": "${max($a, $b)}"
        },
        "headers": {
            "User-Agent": "HttpRunnerPlus"
        }
    }
}

rpc vs. gRPC

HttpRunner+ has both supported net/rpc and gRPC in hashicorp/plugin. It is recommended to use gRPC and this is the default choice.

If you want to run plugin in net/rpc mode, you can set an environment variable HRP_PLUGIN_TYPE=rpc.

$ export HRP_PLUGIN_TYPE=rpc
$ hrp run examples/demo.json
$ hrp boom examples/demo.json

go plugin

The golang official plugin is only supported on Linux, FreeBSD, and macOS. And this solution also has many drawbacks.

create plugin functions

Firstly, you need to define your plugin functions. The functions can be very flexible, only the following restrictions should be complied with.

• plugin package name must be main.
• function names must be capitalized.
• function should return at most one value and one error.

Here is some plugin functions as example.

package main

func SumTwoInt(a, b int) int {
	return a + b
}

func SumInts(args ...int) int {
	var sum int
	for _, arg := range args {
		sum += arg
	}
	return sum
}

func Sum(args ...interface{}) (interface{}, error) {
	var sum float64
	for _, arg := range args {
		switch v := arg.(type) {
		case int:
			sum += float64(v)
		case float64:
			sum += v
		default:
			return nil, fmt.Errorf("unexpected type: %T", arg)
		}
	}
	return sum, nil
}

You can get more examples at examples/plugin/debugtalk.go

build plugin

Then you can build your go plugin with -buildmode=plugin flag to binary file debugtalk.so. The name of debugtalk.so is by convention and should not be changed.

$ go build -buildmode=plugin -o=examples/debugtalk.so examples/plugin/debugtalk.go

It is recommended to place the debugtalk.so file in your project root folder, or you can put it in the parent folder of the target testcase file. HttpRunner+ will search debugtalk.so upward recursively until current working directory or system root dir.

use plugin functions

Then, you can call your defined plugin function in your YAML/JSON testcase at any position.

{
    "name": "get with params",
    "variables": {
        "a": "${SumTwoInt(1,6)}",
        "b": "${SumInts(1,2,3)}",
        "c": "${Sum(1, 2.3, 4)}",
    },
    "request": {
        "method": "GET",
        "url": "/get",
        "params": {
            "foo1": "$c",
            "foo2": "${max($a, $b)}"
        },
        "headers": {
            "User-Agent": "HttpRunnerPlus"
        }
    }
}

Notice: you should use the original function name.