diff --git a/src/text/template/parse/parse.go b/src/text/template/parse/parse.go index 6eb303801b7bec..88aacd1b72b55a 100644 --- a/src/text/template/parse/parse.go +++ b/src/text/template/parse/parse.go @@ -413,9 +413,8 @@ func (t *Tree) pipeline(context string) (pipe *PipeNode) { for { switch token := t.nextNonSpace(); token.typ { case itemRightDelim, itemRightParen: - if len(pipe.Cmds) == 0 { - t.errorf("missing value for %s", context) - } + // At this point, the pipeline is complete + t.checkPipeline(pipe, context) if token.typ == itemRightParen { t.backup() } @@ -430,6 +429,21 @@ func (t *Tree) pipeline(context string) (pipe *PipeNode) { } } +func (t *Tree) checkPipeline(pipe *PipeNode, context string) { + // Reject empty pipelines + if len(pipe.Cmds) == 0 { + t.errorf("missing value for %s", context) + } + // Only the first command of a pipeline can start with a non executable operand + for i, c := range pipe.Cmds[1:] { + switch c.Args[0].Type() { + case NodeBool, NodeDot, NodeNil, NodeNumber, NodeString: + // With A|B|C, pipeline stage 2 is B + t.errorf("non executable command in pipeline stage %d", i+2) + } + } +} + func (t *Tree) parseControl(allowElseIf bool, context string) (pos Pos, line int, pipe *PipeNode, list, elseList *ListNode) { defer t.popVars(len(t.vars)) line = t.lex.lineNumber() diff --git a/src/text/template/parse/parse_test.go b/src/text/template/parse/parse_test.go index 808f9a0b5ed5c5..9e62bd2df6a1aa 100644 --- a/src/text/template/parse/parse_test.go +++ b/src/text/template/parse/parse_test.go @@ -269,6 +269,14 @@ var parseTests = []parseTest{ {"dot after string", `{{"hello".guys}}`, hasError, ""}, {"dot after dot", "{{..E}}", hasError, ""}, {"dot after nil", "{{nil.E}}", hasError, ""}, + // Wrong pipeline + {"wrong pipeline dot", "{{12|.}}", hasError, ""}, + {"wrong pipeline number", "{{.|12|printf}}", hasError, ""}, + {"wrong pipeline string", "{{.|print|\"error\"}}", hasError, ""}, + {"wrong pipeline char", "{{12|print|html|'e'}}", hasError, ""}, + {"wrong pipeline boolean", "{{.|true}}", hasError, ""}, + {"wrong pipeline nil", "{{'c'|nil}}", hasError, ""}, + {"empty pipeline", `{{printf "%d" ( ) }}`, hasError, ""}, } var builtins = map[string]interface{}{ @@ -422,6 +430,12 @@ var errorTests = []parseTest{ {"wrongdot", "{{true.any}}", hasError, `unexpected . after term`}, + {"wrongpipeline", + "{{12|false}}", + hasError, `non executable command in pipeline`}, + {"emptypipeline", + `{{ ( ) }}`, + hasError, `missing value for parenthesized pipeline`}, } func TestErrors(t *testing.T) {