feat(compat): wire compat/formats §4 attestation

.github/workflows/ci.yml

@@ -44,4 +44,4 @@ jobs:
         env:
           # Path the compat-tagged test reads from os.Getenv.
           CRONO_EXPORT_BIN: /tmp/crono-export
-        run: go test -tags=compat -run TestContractDates ./...
+        run: go test -tags=compat -run 'TestContract(Dates|Formats)' ./...

compat_contract_test.go

@@ -17,8 +17,21 @@ import (
 
 	"github.com/quantcli/common/compat"
 	"github.com/quantcli/common/compat/dates"
+	"github.com/quantcli/common/compat/formats"
 )
 
+// cronoSubcommands is the §3/§4 surface for crono — each subcommand
+// owns its own --since/--until and --format flags. Shared between the
+// dates and formats bundles so a single source-of-truth list keeps
+// the two suites in sync.
+var cronoSubcommands = []string{
+	"biometrics",
+	"exercises",
+	"nutrition",
+	"servings",
+	"notes",
+}
+
 func TestContractDates(t *testing.T) {
 	bin := os.Getenv("CRONO_EXPORT_BIN")
 	if bin == "" {
@@ -29,13 +42,32 @@ func TestContractDates(t *testing.T) {
 	// subcommand under a `subcommand=NAME/...` subtree so any single
 	// regression surfaces as a named subtest failure.
 	dates.RunContract(t, compat.Runner{
-		Binary: bin,
-		Subcommands: []string{
-			"biometrics",
-			"exercises",
-			"nutrition",
-			"servings",
-			"notes",
-		},
+		Binary:      bin,
+		Subcommands: cronoSubcommands,
+	})
+}
+
+func TestContractFormats(t *testing.T) {
+	bin := os.Getenv("CRONO_EXPORT_BIN")
+	if bin == "" {
+		t.Skip("CRONO_EXPORT_BIN not set; skipping compat suite")
+	}
+	// crono implements --format markdown (default) and --format json
+	// today; CSV is not yet wired (see cmd/format.go chosenFormat).
+	// SupportedFormats: ["markdown","json"] skips CSVHasHeader with a
+	// named reason rather than failing it.
+	//
+	// SkipDataPath: true opts out of JSONIsArray / CSVHasHeader /
+	// DefaultIsMarkdown — crono's data path requires
+	// CRONOMETER_USERNAME/PASSWORD which the compat CI job does not
+	// provide, so the data-path subtests would fail at "not logged in"
+	// before the codec assertions could run. The parse-level subtests
+	// (HelpDocumentsFormatFlag, UnknownFormatFails,
+	// FlagValidationIsHermetic) still attest the §4 surface.
+	formats.RunContract(t, compat.Runner{
+		Binary:           bin,
+		Subcommands:      cronoSubcommands,
+		SupportedFormats: []string{"markdown", "json"},
+		SkipDataPath:     true,
 	})
 }

go.mod

@@ -3,7 +3,7 @@ module github.com/quantcli/crono-export-cli
 go 1.25.10
 
 require (
-	github.com/quantcli/common/compat v0.0.0-20260510225630-4c588c19cd1b
+	github.com/quantcli/common/compat v0.0.0-20260511224412-1cf4a39648c5
 	github.com/spf13/cobra v1.10.2
 )
 

go.sum

@@ -1,8 +1,8 @@
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
-github.com/quantcli/common/compat v0.0.0-20260510225630-4c588c19cd1b h1:fO7EfkEqzLRC8Ev22jIq05fPs+JwAB7bCDy6FA+GA5k=
-github.com/quantcli/common/compat v0.0.0-20260510225630-4c588c19cd1b/go.mod h1:VBC/zEphSZgCZS1rhWsR3A8EWYSbTkP/MwqWHL7266s=
+github.com/quantcli/common/compat v0.0.0-20260511224412-1cf4a39648c5 h1:UW6c2rz3bbk2Ju0lGv+QqmuU7+SkIQMFkBJPSr+LDGc=
+github.com/quantcli/common/compat v0.0.0-20260511224412-1cf4a39648c5/go.mod h1:VBC/zEphSZgCZS1rhWsR3A8EWYSbTkP/MwqWHL7266s=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
 github.com/spf13/cobra v1.10.2/go.mod h1:7C1pvHqHw5A4vrJfjNwvOdzYu0Gml16OCs2GRiTUUS4=