| 1 | // Package guards turns rules that used to live only as prose in |
| 2 | // AGENTS.md into tests. CARLOS's own rule for this: "A guard a shell |
| 3 | // step can satisfy is a guard a shell step can be wrong about — put |
| 4 | // guards inside the test binary." So these run as part of `go test |
| 5 | // ./...`, not as separate shell greps that a CI step could get subtly |
| 6 | // wrong (or that a shell rewrite could quietly stop running). |
| 7 | // |
| 8 | // This file holds the shared plumbing (repo-root discovery, file |
| 9 | // walking, import parsing) that every rule's test file uses. It carries |
| 10 | // no Test functions of its own. |
| 11 | package guards |
| 12 | |
| 13 | import ( |
| 14 | "go/parser" |
| 15 | "go/token" |
| 16 | "os" |
| 17 | "path/filepath" |
| 18 | "runtime" |
| 19 | "strconv" |
| 20 | "strings" |
| 21 | "testing" |
| 22 | ) |
| 23 | |
| 24 | // module is the module path declared in this repo's go.mod. Used to |
| 25 | // confirm repoRoot found the right go.mod, not some unrelated one on a |
| 26 | // parent path (e.g. if the worktree lives under another Go module). |
| 27 | const module = "amadan.net/oficina/sheets" |
| 28 | |
| 29 | // repoRoot locates the module root by walking up from this source |
| 30 | // file's own location (via runtime.Caller), not from the working |
| 31 | // directory. `go test ./...` runs every package's tests with that |
| 32 | // package's own directory as cwd, so cwd is not a reliable anchor — |
| 33 | // runtime.Caller(0) always points back to this file, wherever it was |
| 34 | // invoked from. |
| 35 | func repoRoot(t *testing.T) string { |
| 36 | t.Helper() |
| 37 | _, thisFile, _, ok := runtime.Caller(0) |
| 38 | if !ok { |
| 39 | t.Fatal("guards: runtime.Caller(0) failed") |
| 40 | } |
| 41 | dir := filepath.Dir(thisFile) |
| 42 | for { |
| 43 | if b, err := os.ReadFile(filepath.Join(dir, "go.mod")); err == nil { |
| 44 | if strings.Contains(string(b), "module "+module+"\n") { |
| 45 | return dir |
| 46 | } |
| 47 | } |
| 48 | parent := filepath.Dir(dir) |
| 49 | if parent == dir { |
| 50 | t.Fatalf("guards: no go.mod for module %q found above %s", module, filepath.Dir(thisFile)) |
| 51 | } |
| 52 | dir = parent |
| 53 | } |
| 54 | } |
| 55 | |
| 56 | // skipDirs names directories goFiles never descends into: version |
| 57 | // control, dependency/vendor trees, and dotfiles-style tooling |
| 58 | // directories that hold no Go source of ours. |
| 59 | func skipDir(name string) bool { |
| 60 | if strings.HasPrefix(name, ".") { |
| 61 | return true |
| 62 | } |
| 63 | switch name { |
| 64 | case "vendor", "node_modules", "testdata": |
| 65 | return true |
| 66 | } |
| 67 | return false |
| 68 | } |
| 69 | |
| 70 | // goFiles returns the repo-relative path of every *.go file under root. |
| 71 | func goFiles(t *testing.T, root string) []string { |
| 72 | t.Helper() |
| 73 | var files []string |
| 74 | err := filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error { |
| 75 | if err != nil { |
| 76 | return err |
| 77 | } |
| 78 | if d.IsDir() { |
| 79 | if path != root && skipDir(d.Name()) { |
| 80 | return filepath.SkipDir |
| 81 | } |
| 82 | return nil |
| 83 | } |
| 84 | if strings.HasSuffix(path, ".go") { |
| 85 | files = append(files, path) |
| 86 | } |
| 87 | return nil |
| 88 | }) |
| 89 | if err != nil { |
| 90 | t.Fatalf("guards: walk %s: %v", root, err) |
| 91 | } |
| 92 | return files |
| 93 | } |
| 94 | |
| 95 | // relPath is filepath.Rel with the guards-package error-handling |
| 96 | // boilerplate folded in, since every rule needs a repo-relative path |
| 97 | // for its failure messages. |
| 98 | func relPath(t *testing.T, root, path string) string { |
| 99 | t.Helper() |
| 100 | rel, err := filepath.Rel(root, path) |
| 101 | if err != nil { |
| 102 | t.Fatalf("guards: rel %s: %v", path, err) |
| 103 | } |
| 104 | return filepath.ToSlash(rel) |
| 105 | } |
| 106 | |
| 107 | // fileImports returns the import paths a Go source file declares. It |
| 108 | // parses in ImportsOnly mode — the cheapest mode that still sees the |
| 109 | // import block — so walking every file in the tree on every test run |
| 110 | // stays fast. |
| 111 | func fileImports(t *testing.T, path string) []string { |
| 112 | t.Helper() |
| 113 | fset := token.NewFileSet() |
| 114 | f, err := parser.ParseFile(fset, path, nil, parser.ImportsOnly) |
| 115 | if err != nil { |
| 116 | t.Fatalf("guards: parse %s: %v", path, err) |
| 117 | } |
| 118 | imports := make([]string, 0, len(f.Imports)) |
| 119 | for _, imp := range f.Imports { |
| 120 | p, err := strconv.Unquote(imp.Path.Value) |
| 121 | if err != nil { |
| 122 | t.Fatalf("guards: unquote import in %s: %v", path, err) |
| 123 | } |
| 124 | imports = append(imports, p) |
| 125 | } |
| 126 | return imports |
| 127 | } |
| 128 | |
| 129 | // inTree reports whether rel — a repo-relative file path — lives inside |
| 130 | // the directory tree rooted at dir (dir itself, or any subdirectory of |
| 131 | // it, at any depth). Used instead of comparing filepath.Dir(rel) == dir |
| 132 | // so a rule means "this whole package tree" and not just "files whose |
| 133 | // immediate parent happens to match" — a future subpackage (e.g. |
| 134 | // calc/functions) must inherit the rule, not silently fall outside it. |
| 135 | func inTree(rel, dir string) bool { |
| 136 | return strings.HasPrefix(rel, dir+"/") |
| 137 | } |
| 138 | |
| 139 | // importUnder reports whether imp is base itself, or an import path |
| 140 | // nested under base (base plus "/something"). Used instead of plain |
| 141 | // equality so a forbidden import stays forbidden if it grows |
| 142 | // subpackages later (e.g. a future .../store/schema), rather than the |
| 143 | // check silently narrowing to just the package's root import path. |
| 144 | func importUnder(imp, base string) bool { |
| 145 | return imp == base || strings.HasPrefix(imp, base+"/") |
| 146 | } |
| 147 | |
amadan