commands: add a helper to generate testing regex for CLI output

1 files changed, 62 insertions, 0 deletions

diff --git a/commands/cmdtest/regex.go b/commands/cmdtest/regex.go
new file mode 100644
index 00000000..0b9cb672
--- /dev/null
+++ b/commands/cmdtest/regex.go
@@ -0,0 +1,62 @@
+package cmdtest
+
+import (
+	"regexp"
+	"strings"
+)
+
+const ExpId = "\x07id\x07"
+const ExpHumanId = "\x07human-id\x07"
+const ExpTimestamp = "\x07timestamp\x07"
+const ExpISO8601 = "\x07iso8601\x07"
+
+const ExpOrgModeDate = "\x07org-mode-date\x07"
+
+// MakeExpectedRegex transform a raw string of an expected output into a regex suitable for testing.
+// Some markers like ExpId are available to substitute the appropriate regex for element that can vary randomly.
+func MakeExpectedRegex(input string) string {
+	var substitutes = map[string]string{
+		ExpId:          `[0-9a-f]{64}`,
+		ExpHumanId:     `[0-9a-f]{7}`,
+		ExpTimestamp:   `[0-9]{7,10}`,
+		ExpISO8601:     `\d{4}(-\d\d(-\d\d(T\d\d:\d\d(:\d\d)?(\.\d+)?(([+-]\d\d:\d\d)|Z)?)?)?)?`,
+		ExpOrgModeDate: `\d\d\d\d-\d\d-\d\d [[:alpha:]]{3} \d\d:\d\d`,
+	}
+
+	escaped := []rune(regexp.QuoteMeta(input))
+
+	var result strings.Builder
+	var inSubstitute bool
+	var substitute strings.Builder
+
+	result.WriteString("^")
+
+	for i := 0; i < len(escaped); i++ {
+		r := escaped[i]
+		if !inSubstitute && r == '\x07' {
+			substitute.Reset()
+			substitute.WriteRune(r)
+			inSubstitute = true
+			continue
+		}
+		if inSubstitute && r == '\x07' {
+			substitute.WriteRune(r)
+			sub, ok := substitutes[substitute.String()]
+			if !ok {
+				panic("unknown substitute: " + substitute.String())
+			}
+			result.WriteString(sub)
+			inSubstitute = false
+			continue
+		}
+		if inSubstitute {
+			substitute.WriteRune(r)
+		} else {
+			result.WriteRune(r)
+		}
+	}
+
+	result.WriteString("$")
+
+	return result.String()
+}