tpl: Do not return errors in substr for out-of-bounds cases

Most other substr implementations don't error out in out-of-bounds cases
but simply return an empty string (or a value that's printed as an empty
string). We'll follow their lead and not exit template execution.  Allow
the user decide what to do with the empty result.

Fixes #8113
This commit is contained in:
Cameron Moore 2021-01-03 12:01:42 -06:00 committed by Bjørn Erik Pedersen
parent 788e50ad3a
commit 8a26ab0bc5
2 changed files with 7 additions and 7 deletions

View file

@ -16,7 +16,6 @@ package strings
import (
"errors"
"fmt"
"html/template"
"strings"
"unicode/utf8"
@ -322,7 +321,7 @@ func (ns *Namespace) Substr(a interface{}, nums ...interface{}) (string, error)
}
if start > rlen-1 {
return "", fmt.Errorf("start position out of bounds for %d-byte string", rlen)
return "", nil
}
end := rlen
@ -337,7 +336,7 @@ func (ns *Namespace) Substr(a interface{}, nums ...interface{}) (string, error)
}
if start >= end {
return "", fmt.Errorf("calculated start position greater than end position: %d > %d", start, end)
return "", nil
}
if end < 0 {

View file

@ -451,9 +451,9 @@ func TestSubstr(t *testing.T) {
{"abcdef", -3, 1, "d"},
{"abcdef", 0, -1, "abcde"},
{"abcdef", 2, -1, "cde"},
{"abcdef", 4, -4, false},
{"abcdef", 7, 1, false},
{"abcdef", 6, nil, false},
{"abcdef", 4, -4, ""},
{"abcdef", 7, 1, ""},
{"abcdef", 6, nil, ""},
{"abcdef", 1, 100, "bcdef"},
{"abcdef", -100, 3, "abc"},
{"abcdef", -3, -1, "de"},
@ -476,6 +476,7 @@ func TestSubstr(t *testing.T) {
{"abcdef", "doo", nil, false},
{"abcdef", "doo", "doo", false},
{"abcdef", 1, "doo", false},
{"", 0, nil, ""},
} {
var result string
@ -491,7 +492,7 @@ func TestSubstr(t *testing.T) {
continue
}
c.Assert(err, qt.IsNil)
c.Assert(err, qt.IsNil, qt.Commentf("%v", test))
c.Check(result, qt.Equals, test.expect, qt.Commentf("%v", test))
}