package guards

import (
	"testing"
)

// excelizeImport is the XLSX library's import path.
const excelizeImport = "github.com/xuri/excelize/v2"

// excelizeHome is the package tree allowed to import it — xlsx itself
// and any subpackage of it. Matched as a tree, not by exact directory
// equality: equality would make a future xlsx subpackage look like it
// was outside home and wrongly forbid it from importing excelize (the
// over-strict direction — a false positive, not a leak — but still
// wrong). Confining excelize's quirks to this one tree keeps the XLSX
// format's weirdness from leaking into the rest of Sheets.
const excelizeHome = "internal/sheets/xlsx"

// TestExcelizeConfinedToXLSXPackage fails on any excelize import outside
// the internal/sheets/xlsx tree.
func TestExcelizeConfinedToXLSXPackage(t *testing.T) {
	root := repoRoot(t)
	for _, path := range goFiles(t, root) {
		rel := relPath(t, root, path)
		if inTree(rel, excelizeHome) {
			continue
		}
		for _, imp := range fileImports(t, path) {
			if imp == excelizeImport {
				t.Errorf("%s: imports %q, confined to %s (excelize confinement)", rel, excelizeImport, excelizeHome)
			}
		}
	}
}