text/template: check for literals in chain of terms
The current parser ignores obvious errors such as:
{{0.1.E}}
{{true.any}}
{{"hello".wrong}}
{{nil.E}}
The common problem is that a chain is built from
a literal value. It then panics at execution time.
Furthermore, a double dot triggers the same behavior:
{{..E}}
Addresses a TODO left in Tree.operand to catch these
errors at parsing time.
Note that identifiers can include a '.', and pipelines
could return an object which a field can be derived
from (like a variable), so they are excluded from the check.
Fixes #10615
Change-Id: I903706d1c17861b5a8354632c291e73c9c0bc4e1
Reviewed-on: https://go-review.googlesource.com/9621
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/src/text/template/parse/parse_test.go b/src/text/template/parse/parse_test.go
index faac06f..a2ca98b 100644
--- a/src/text/template/parse/parse_test.go
+++ b/src/text/template/parse/parse_test.go
@@ -260,6 +260,14 @@
{"bug1a", "{{$x:=.}}{{$x!2}}", hasError, ""}, // ! is just illegal here.
{"bug1b", "{{$x:=.}}{{$x+2}}", hasError, ""}, // $x+2 should not parse as ($x) (+2).
{"bug1c", "{{$x:=.}}{{$x +2}}", noError, "{{$x := .}}{{$x +2}}"}, // It's OK with a space.
+ // dot following a literal value
+ {"dot after integer", "{{1.E}}", hasError, ""},
+ {"dot after float", "{{0.1.E}}", hasError, ""},
+ {"dot after boolean", "{{true.E}}", hasError, ""},
+ {"dot after char", "{{'a'.any}}", hasError, ""},
+ {"dot after string", `{{"hello".guys}}`, hasError, ""},
+ {"dot after dot", "{{..E}}", hasError, ""},
+ {"dot after nil", "{{nil.E}}", hasError, ""},
}
var builtins = map[string]interface{}{
@@ -378,7 +386,7 @@
hasError, `unexpected ")"`},
{"space",
"{{`x`3}}",
- hasError, `missing space?`},
+ hasError, `in operand`},
{"idchar",
"{{a#}}",
hasError, `'#'`},
@@ -410,6 +418,9 @@
{"undefvar",
"{{$a}}",
hasError, `undefined variable`},
+ {"wrongdot",
+ "{{true.any}}",
+ hasError, `unexpected . after term`},
}
func TestErrors(t *testing.T) {
