caddyfile: Implement variadics for import args placeholders (#5249)

* implement variadic placeholders
imported snippets reflect actual lines in file

* add import directive line number for imported snippets
add tests for parsing

* add realfile field to help debug import cycle detection.

* use file field to reflect import chain

* Switch syntax, deprecate old syntax, refactoring

- Moved the import args handling to a separate file
- Using {args[0:1]} syntax now
- Deprecate {args.*} syntax
- Use a replacer map for better control over the parsing
- Add plenty of warnings when invalid placeholders are detected
- Renaming variables, cleanup comments for readability
- More tests to cover edgecases I could think of
- Minor cleanup to snippet tracking in tokens, drop a redundant boolean field in tokens

---------

Co-authored-by: Francis Lavoie <lavofr@gmail.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/caddyconfig/httpcaddyfile/builtins_test.go b/caddyconfig/httpcaddyfile/builtins_test.go
index bd5e116..6ae4b31 100644
--- a/caddyconfig/httpcaddyfile/builtins_test.go
+++ b/caddyconfig/httpcaddyfile/builtins_test.go
@@ -1,6 +1,7 @@
 package httpcaddyfile
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/caddyserver/caddy/v2/caddyconfig/caddyfile"
@@ -213,3 +214,45 @@ func TestRedirDirectiveSyntax(t *testing.T) {
 		}
 	}
 }
+
+func TestImportErrorLine(t *testing.T) {
+	for i, tc := range []struct {
+		input     string
+		errorFunc func(err error) bool
+	}{
+		{
+			input: `(t1) {
+					abort {args[:]}
+				}
+				:8080 {
+					import t1
+					import t1 true
+				}`,
+			errorFunc: func(err error) bool {
+				return err != nil && strings.Contains(err.Error(), "Caddyfile:6 (import t1):2")
+			},
+		},
+		{
+			input: `(t1) {
+					abort {args[:]}
+				}
+				:8080 {
+					import t1 true
+				}`,
+			errorFunc: func(err error) bool {
+				return err != nil && strings.Contains(err.Error(), "Caddyfile:5 (import t1):2")
+			},
+		},
+	} {
+		adapter := caddyfile.Adapter{
+			ServerType: ServerType{},
+		}
+
+		_, _, err := adapter.Adapt([]byte(tc.input), nil)
+
+		if !tc.errorFunc(err) {
+			t.Errorf("Test %d error expectation failed, got %s", i, err)
+			continue
+		}
+	}
+}