From 1b2cdd207a75432314f4780d4b0e20bec40c005b Mon Sep 17 00:00:00 2001
From: debugtalk <mail@debugtalk.com>
Date: Sun, 3 Oct 2021 19:46:09 +0800
Subject: [PATCH] feat: eval literal

---
 go.mod         |  1 +
 go.sum         |  2 ++
 parser.go      | 28 ++++++++++++++++++++++++++--
 parser_test.go | 25 +++++++++++++++++++++++++
 4 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/go.mod b/go.mod
index df60a9f1..a0392e52 100644
--- a/go.mod
+++ b/go.mod
@@ -8,6 +8,7 @@ require (
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/imroc/req v0.3.0 // indirect
 	github.com/jmespath/go-jmespath v0.4.0 // indirect
+	github.com/maja42/goval v1.2.1 // indirect
 	github.com/myzhan/boomer v1.6.0
 	github.com/olekukonko/tablewriter v0.0.5 // indirect
 	github.com/shirou/gopsutil v3.21.8+incompatible // indirect
diff --git a/go.sum b/go.sum
index 8c81c378..5ebb7ba7 100644
--- a/go.sum
+++ b/go.sum
@@ -13,6 +13,8 @@ github.com/imroc/req v0.3.0/go.mod h1:F+NZ+2EFSo6EFXdeIbpfE9hcC233id70kf0byW97Ca
 github.com/jmespath/go-jmespath v0.4.0 h1:BEgLn5cpjn8UN1mAw4NjwDrS35OdebyEtFe+9YPoQUg=
 github.com/jmespath/go-jmespath v0.4.0/go.mod h1:T8mJZnbsbmF+m6zOOFylbeCJqk5+pHWvzYPziyZiYoo=
 github.com/jmespath/go-jmespath/internal/testify v1.5.1/go.mod h1:L3OGu8Wl2/fWfCI6z80xFu9LTZmf1ZRjMHUOPmWr69U=
+github.com/maja42/goval v1.2.1 h1:fyEgzddqPgCZsKcFLk4C6SdCHyEaAHYvtZG4mGzQOHU=
+github.com/maja42/goval v1.2.1/go.mod h1:42LU+BQXL/veE9jnTTUOSj38GRmOTSThYSXRVodI5J4=
 github.com/mattn/go-runewidth v0.0.9 h1:Lm995f3rfxdpd6TSmuVCHVb/QhupuXlYr8sCI/QdE+0=
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
 github.com/myzhan/boomer v1.6.0 h1:xjgvmhDjgU9IEKnB7nU1HyoVEfj8SuuU3u6oY3Nugj0=
diff --git a/parser.go b/parser.go
index ca10c30b..c47be9f3 100644
--- a/parser.go
+++ b/parser.go
@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"github.com/httprunner/httpboomer/builtin"
+	"github.com/maja42/goval"
 )
 
 func parseStep(step IStep, config *TConfig) *TStep {
@@ -77,13 +78,15 @@ func parseData(raw interface{}, variablesMapping map[string]interface{}) interfa
 }
 
 const (
-	regexVariable     = `[a-zA-Z_]\w*` // variable name should start with a letter or underscore
-	regexFunctionName = `[a-zA-Z_]\w*` // function name should start with a letter or underscore
+	regexVariable     = `[a-zA-Z_]\w*`  // variable name should start with a letter or underscore
+	regexFunctionName = `[a-zA-Z_]\w*`  // function name should start with a letter or underscore
+	regexNumber       = `-?\d+(\.\d+)?` // match number, e.g. 123, -123, 1.23, -1.23
 )
 
 var (
 	regexCompileVariable = regexp.MustCompile(fmt.Sprintf(`\$\{(%s)\}|\$(%s)`, regexVariable, regexVariable))     // parse ${var} or $var
 	regexCompileFunction = regexp.MustCompile(fmt.Sprintf(`\$\{(%s)\(([\$\w\.\-/\s=,]*)\)\}`, regexFunctionName)) // parse ${func1($a, $b)}
+	regexCompileNumber   = regexp.MustCompile(regexNumber)                                                        // parse number
 )
 
 // parseString parse string with variables
@@ -226,3 +229,24 @@ func callFunc(funcName string, arguments ...interface{}) (interface{}, error) {
 	log.Printf("[callFunction] output result: %+v(%T)", result, result)
 	return result, nil
 }
+
+var eval = goval.NewEvaluator()
+
+// literalEval parse string to number if possible
+// e.g. "123" => 123
+//      "1.23" => 1.23
+//      "abc" => "abc"
+//      "$var" => "$var"
+func literalEval(raw string) (interface{}, error) {
+	// check if raw is a number
+	if !regexCompileNumber.Match([]byte(raw)) {
+		return raw, nil
+	}
+
+	// eval string to number
+	result, err := eval.Evaluate(raw, nil, nil)
+	if err != nil {
+		return raw, err
+	}
+	return result, nil
+}
diff --git a/parser_test.go b/parser_test.go
index b1702625..92190bf9 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -315,3 +315,28 @@ func TestCallFunction(t *testing.T) {
 		t.Fail()
 	}
 }
+
+func TestLiteralEval(t *testing.T) {
+	testData := []struct {
+		expr   string
+		expect interface{}
+	}{
+		{"123", 123},
+		{"1.23", 1.23},
+		{"-123", -123},
+		{"-1.23", -1.23},
+		{"abc", "abc"},
+		{"$var", "$var"},
+		{"", ""},
+	}
+
+	for _, data := range testData {
+		value, err := literalEval(data.expr)
+		if !assert.Nil(t, err) {
+			t.Fail()
+		}
+		if !assert.Equal(t, data.expect, value) {
+			t.Fail()
+		}
+	}
+}