| 1 | package main |
| 2 | |
| 3 | import ( |
| 4 | "go/ast" |
| 5 | "go/parser" |
| 6 | "go/token" |
| 7 | "os" |
| 8 | "os/exec" |
| 9 | "strconv" |
| 10 | "strings" |
| 11 | "testing" |
| 12 | ) |
| 13 | |
| 14 | // dispatchedSubcommands reads main.go and returns the case strings of the |
| 15 | // switch that dispatches os.Args[1]. Reading the source (rather than keeping a |
| 16 | // second hand-written list) is the point: this is what makes the drift test |
| 17 | // below authoritative instead of just another copy to forget. |
| 18 | func dispatchedSubcommands(t *testing.T) []string { |
| 19 | t.Helper() |
| 20 | f, err := parser.ParseFile(token.NewFileSet(), "main.go", nil, 0) |
| 21 | if err != nil { |
| 22 | t.Fatalf("parse main.go: %v", err) |
| 23 | } |
| 24 | var found []string |
| 25 | ast.Inspect(f, func(n ast.Node) bool { |
| 26 | fn, ok := n.(*ast.FuncDecl) |
| 27 | if !ok || fn.Name.Name != "main" { |
| 28 | return true |
| 29 | } |
| 30 | ast.Inspect(fn, func(n ast.Node) bool { |
| 31 | sw, ok := n.(*ast.SwitchStmt) |
| 32 | // Only the switch on os.Args[1] — main() contains others. |
| 33 | if !ok || !strings.Contains(exprText(sw.Tag), "os.Args[1]") { |
| 34 | return true |
| 35 | } |
| 36 | for _, stmt := range sw.Body.List { |
| 37 | cc, ok := stmt.(*ast.CaseClause) |
| 38 | if !ok { |
| 39 | continue |
| 40 | } |
| 41 | for _, e := range cc.List { |
| 42 | if lit, ok := e.(*ast.BasicLit); ok && lit.Kind == token.STRING { |
| 43 | if s, err := strconv.Unquote(lit.Value); err == nil { |
| 44 | found = append(found, s) |
| 45 | } |
| 46 | } |
| 47 | } |
| 48 | } |
| 49 | return false |
| 50 | }) |
| 51 | return false |
| 52 | }) |
| 53 | if len(found) == 0 { |
| 54 | t.Fatal("found no dispatch cases in main() — has the switch moved? this test must be updated with it") |
| 55 | } |
| 56 | return found |
| 57 | } |
| 58 | |
| 59 | // exprText renders an expression enough to recognise os.Args[1]. |
| 60 | func exprText(e ast.Expr) string { |
| 61 | idx, ok := e.(*ast.IndexExpr) |
| 62 | if !ok { |
| 63 | return "" |
| 64 | } |
| 65 | sel, ok := idx.X.(*ast.SelectorExpr) |
| 66 | if !ok { |
| 67 | return "" |
| 68 | } |
| 69 | pkg, ok := sel.X.(*ast.Ident) |
| 70 | if !ok { |
| 71 | return "" |
| 72 | } |
| 73 | lit, ok := idx.Index.(*ast.BasicLit) |
| 74 | if !ok { |
| 75 | return "" |
| 76 | } |
| 77 | return pkg.Name + "." + sel.Sel.Name + "[" + lit.Value + "]" |
| 78 | } |
| 79 | |
| 80 | // TestUsageCoversEverySubcommand is the contract: `lchat help` lists exactly |
| 81 | // what main() dispatches. A new subcommand with no help entry is a silent |
| 82 | // feature; a help entry that dispatches nowhere is a lie in the CLI's own |
| 83 | // documentation. Both fail here. |
| 84 | func TestUsageCoversEverySubcommand(t *testing.T) { |
| 85 | documented := map[string]bool{} |
| 86 | for _, c := range subcommands { |
| 87 | if documented[c.name] { |
| 88 | t.Errorf("subcommands lists %q twice", c.name) |
| 89 | } |
| 90 | documented[c.name] = true |
| 91 | } |
| 92 | dispatched := map[string]bool{} |
| 93 | for _, name := range dispatchedSubcommands(t) { |
| 94 | dispatched[name] = true |
| 95 | if !documented[name] { |
| 96 | t.Errorf("main() dispatches %q but `lchat help` does not list it — add it to subcommands", name) |
| 97 | } |
| 98 | } |
| 99 | for _, c := range subcommands { |
| 100 | if !dispatched[c.name] { |
| 101 | t.Errorf("`lchat help` lists %q but main() does not dispatch it", c.name) |
| 102 | } |
| 103 | } |
| 104 | } |
| 105 | |
| 106 | func TestLooksLikeFlag(t *testing.T) { |
| 107 | for _, tc := range []struct { |
| 108 | arg string |
| 109 | flag bool |
| 110 | }{ |
| 111 | {"-db", true}, |
| 112 | {"--db", true}, |
| 113 | {"-h", true}, |
| 114 | {"-addr=:1747", true}, |
| 115 | {"-", false}, // not a flag: a typo we should name, not pass to flag parsing |
| 116 | {"router", false}, |
| 117 | {"routes", false}, |
| 118 | {"", false}, |
| 119 | } { |
| 120 | if got := looksLikeFlag(tc.arg); got != tc.flag { |
| 121 | t.Errorf("looksLikeFlag(%q) = %v, want %v", tc.arg, got, tc.flag) |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | func TestIsSubcommand(t *testing.T) { |
| 127 | for _, name := range []string{"router", "bootstrap", "links", "version"} { |
| 128 | if !isSubcommand(name) { |
| 129 | t.Errorf("isSubcommand(%q) = false, want true", name) |
| 130 | } |
| 131 | } |
| 132 | // The words that used to boot a server instead of erroring. |
| 133 | for _, name := range []string{"routes", "help", "", "Router", "add_instance"} { |
| 134 | if isSubcommand(name) { |
| 135 | t.Errorf("isSubcommand(%q) = true, want false", name) |
| 136 | } |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | func TestWriteUsageListsEveryCommand(t *testing.T) { |
| 141 | var sb strings.Builder |
| 142 | writeUsage(&sb) |
| 143 | out := sb.String() |
| 144 | for _, c := range subcommands { |
| 145 | if !strings.Contains(out, c.name) { |
| 146 | t.Errorf("usage output omits %q", c.name) |
| 147 | } |
| 148 | if c.blurb == "" { |
| 149 | t.Errorf("%q has no blurb", c.name) |
| 150 | } |
| 151 | } |
| 152 | if !strings.Contains(out, "lchat <command>") { |
| 153 | t.Error("usage output should show the command form") |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | // TestCheckSubcommandExits covers the behaviour that matters — the exit code |
| 158 | // and stream — by re-running this test binary as a helper, since |
| 159 | // checkSubcommand calls os.Exit. `help` must succeed on stdout; an unknown |
| 160 | // word must fail on stderr; a flag must return so main() falls through to the |
| 161 | // single-instance form. |
| 162 | func TestCheckSubcommandExits(t *testing.T) { |
| 163 | for _, tc := range []struct { |
| 164 | name, arg string |
| 165 | wantCode int |
| 166 | wantStderr bool |
| 167 | wantText string |
| 168 | }{ |
| 169 | {"help", "help", 0, false, "Commands:"}, |
| 170 | {"unknown word", "routes", 2, true, `unknown command "routes"`}, |
| 171 | {"bare dash", "-", 2, true, "unknown command"}, |
| 172 | {"flag falls through", "-db", 0, false, "FELL-THROUGH"}, |
| 173 | } { |
| 174 | t.Run(tc.name, func(t *testing.T) { |
| 175 | cmd := exec.Command(os.Args[0], "-test.run=TestCheckSubcommandHelper") |
| 176 | cmd.Env = append(os.Environ(), "LCHAT_SUBCOMMAND_HELPER="+tc.arg) |
| 177 | var stdout, stderr strings.Builder |
| 178 | cmd.Stdout, cmd.Stderr = &stdout, &stderr |
| 179 | err := cmd.Run() |
| 180 | |
| 181 | code := 0 |
| 182 | if ee, ok := err.(*exec.ExitError); ok { |
| 183 | code = ee.ExitCode() |
| 184 | } else if err != nil { |
| 185 | t.Fatalf("run helper: %v", err) |
| 186 | } |
| 187 | if code != tc.wantCode { |
| 188 | t.Errorf("exit code = %d, want %d (stderr: %s)", code, tc.wantCode, stderr.String()) |
| 189 | } |
| 190 | stream, where := stdout.String(), "stdout" |
| 191 | if tc.wantStderr { |
| 192 | stream, where = stderr.String(), "stderr" |
| 193 | } |
| 194 | if !strings.Contains(stream, tc.wantText) { |
| 195 | t.Errorf("%s = %q, want it to contain %q", where, stream, tc.wantText) |
| 196 | } |
| 197 | }) |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | // TestCheckSubcommandHelper is not a real test: it is the subprocess body for |
| 202 | // TestCheckSubcommandExits, and does nothing unless that env var is set. |
| 203 | func TestCheckSubcommandHelper(t *testing.T) { |
| 204 | arg, ok := os.LookupEnv("LCHAT_SUBCOMMAND_HELPER") |
| 205 | if !ok { |
| 206 | t.Skip("helper process only") |
| 207 | } |
| 208 | checkSubcommand(arg) |
| 209 | // Only reached for a flag — the case that must still start an instance. |
| 210 | os.Stdout.WriteString("FELL-THROUGH\n") |
| 211 | os.Exit(0) |
| 212 | } |
| 213 | |
amadan