ref: 51cabe6fafe5b18ce27962b7ec469f69fd5e2229
parent: be44345272276264719ede32447ce62fa92aa508
	author: Tatsushi Demachi <tdemachi@gmail.com>
	date: Sat Jun  6 20:21:14 EDT 2015
	
Fix substr tpl func's int type variant issue `substr` template function takes one or two range arguments. Both arguments must be int type values but if it is used with a calclation function e.g. `add`, `len` etc, it causes a wrong type error. This fixes the issue to allow the function to take other integer type variant like `int64` etc. This also includes a small fix on no range argument case. Fix #1190
--- a/tpl/template_funcs.go
+++ b/tpl/template_funcs.go
@@ -170,7 +170,7 @@
// In addition, borrowing from the extended behavior described at http://php.net/substr,
// if length is given and is negative, then that many characters will be omitted from
// the end of string.
-func Substr(a interface{}, nums ...int) (string, error) {+func Substr(a interface{}, nums ...interface{}) (string, error) {aStr, err := cast.ToStringE(a)
 	if err != nil {return "", err
@@ -177,13 +177,38 @@
}
var start, length int
+	toInt := func (v interface{}, message string) (int, error) {+		switch i := v.(type) {+ case int:
+ return i, nil
+ case int8:
+ return int(i), nil
+ case int16:
+ return int(i), nil
+ case int32:
+ return int(i), nil
+ case int64:
+ return int(i), nil
+ default:
+ return 0, errors.New(message)
+ }
+ }
+
 	switch len(nums) {+ case 0:
+		return "", errors.New("too less arguments")case 1:
- start = nums[0]
+		if start, err = toInt(nums[0], "start argument must be integer"); err != nil {+ return "", err
+ }
length = len(aStr)
case 2:
- start = nums[0]
- length = nums[1]
+		if start, err = toInt(nums[0], "start argument must be integer"); err != nil {+ return "", err
+ }
+		if length, err = toInt(nums[1], "length argument must be integer"); err != nil {+ return "", err
+ }
default:
 		return "", errors.New("too many arguments")}
--- a/tpl/template_funcs_test.go
+++ b/tpl/template_funcs_test.go
@@ -317,10 +317,12 @@
}
 func TestSubstr(t *testing.T) {+ var err error
+ var n int
 	for i, this := range []struct { 		v1     interface{}- v2 int
- v3 int
+		v2     interface{}+		v3     interface{} 		expect interface{} 	}{ 		{"abc", 1, 2, "bc"},@@ -334,12 +336,31 @@
 		{"abcdef", 1, 100, "bcdef"}, 		{"abcdef", -100, 3, "abc"}, 		{"abcdef", -3, -1, "de"},+		{"abcdef", 2, nil, "cdef"},+		{"abcdef", int8(2), nil, "cdef"},+		{"abcdef", int16(2), nil, "cdef"},+		{"abcdef", int32(2), nil, "cdef"},+		{"abcdef", int64(2), nil, "cdef"},+		{"abcdef", 2, int8(3), "cde"},+		{"abcdef", 2, int16(3), "cde"},+		{"abcdef", 2, int32(3), "cde"},+		{"abcdef", 2, int64(3), "cde"}, 		{123, 1, 3, "23"}, 		{1.2e3, 0, 4, "1200"}, 		{tstNoStringer{}, 0, 1, false},+		{"abcdef", 2.0, nil, false},+		{"abcdef", 2.0, 2, false},+		{"abcdef", 2, 2.0, false}, 	} {- result, err := Substr(this.v1, this.v2, this.v3)
+ var result string
+ n = i
+		if this.v3 == nil {+ result, err = Substr(this.v1, this.v2)
+		} else {+ result, err = Substr(this.v1, this.v2, this.v3)
+ }
+
 		if b, ok := this.expect.(bool); ok && !b { 			if err == nil { 				t.Errorf("[%d] Substr didn't return an expected error", i)@@ -353,6 +374,18 @@
 				t.Errorf("[%d] got %s but expected %s", i, result, this.expect)}
}
+ }
+
+ n++
+	_, err = Substr("abcdef")+	if err == nil {+		t.Errorf("[%d] Substr didn't return an expected error", n)+ }
+
+ n++
+	_, err = Substr("abcdef", 1, 2, 3)+	if err == nil {+		t.Errorf("[%d] Substr didn't return an expected error", n)}
}
--
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