fix(analytics): use official Mixpanel Go SDK and drop redundant interface test

Review feedback from @mabd-dev:

1. Swap `github.com/dukex/mixpanel` for the official
   `github.com/mixpanel/mixpanel-go` SDK referenced in
   https://docs.mixpanel.com/docs/tracking-methods/sdks/go.

   The official SDK exposes `NewApiClient(token)` and
   `Track(ctx, []*Event)` instead of the dukex SDK's
   `New(token, "")` / `Track(distinctID, event, *Event)`.
   MixpanelAnalytics now constructs events via
   `client.NewEvent(event, distinctID, properties)` and calls
   `client.Track(context.Background(), []*Event{ev})`. The Analytics
   interface is unchanged, so no callers are affected.

   Also dropped the trailing `var _ = context.Background` line - it
   was a placeholder for the old SDK's missing context support; the
   new SDK takes a real context.Context.

2. Remove `TestAnalytics_InterfaceIsSatisfied` from
   analytics_test.go. The `var _ Analytics = ...` declarations at the
   bottom of analytics.go already enforce this at compile time, so
   the test adds no coverage.

Verified: go build ./..., go vet ./..., go test ./... all pass.

Author: Matt Van Horn

go.mod

@@ -7,9 +7,9 @@ require (
 	github.com/charmbracelet/bubbles v0.21.0
 	github.com/charmbracelet/bubbletea v1.3.6
 	github.com/charmbracelet/lipgloss v1.1.0
-	github.com/dukex/mixpanel v1.0.1
 	github.com/fatih/color v1.18.0
 	github.com/mattn/go-runewidth v0.0.16
+	github.com/mixpanel/mixpanel-go v1.2.1
 	github.com/muesli/reflow v0.3.0
 	github.com/muesli/termenv v0.16.0
 	github.com/pelletier/go-toml/v2 v2.2.4

go.sum

@@ -23,14 +23,16 @@ github.com/charmbracelet/x/exp/golden v0.0.0-20241011142426-46044092ad91/go.mod
 github.com/charmbracelet/x/term v0.2.1 h1:AQeHeLZ1OqSXhrAWpYUtZyX1T3zVxfpZuEQMIQaGIAQ=
 github.com/charmbracelet/x/term v0.2.1/go.mod h1:oQ4enTYFV7QN4m0i9mzHrViD7TQKvNEEkHUMCmsxdUg=
 github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
-github.com/dukex/mixpanel v1.0.1 h1:IQ3qBjtgltF044jU9+i6MubdDdpc8PKpK9yvfawRgeE=
-github.com/dukex/mixpanel v1.0.1/go.mod h1:080BDsRRMzAxViWT3OjlQaMW9nhaIEXDHHtGeDK60b8=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f h1:Y/CXytFA4m6baUTXGLOoWe4PQhGxaX0KpnayAqC48p4=
 github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f/go.mod h1:vw97MGsxSvLiUE2X8qFplwetxpGLQrlU1Q9AUEIzCaM=
 github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
 github.com/fatih/color v1.18.0/go.mod h1:4FelSpRwEGDpQ12mAdzqdOukCy4u8WUtOY6lkT/6HfU=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/jarcoal/httpmock v1.3.1 h1:iUx3whfZWVf3jT01hQTO/Eo5sAYtB2/rqaUuOtpInww=
+github.com/jarcoal/httpmock v1.3.1/go.mod h1:3yb8rc4BI7TCBhFY8ng0gjuLKJNquuDNiPaZjnENuYg=
 github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY=
 github.com/lucasb-eyer/go-colorful v1.2.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
@@ -43,6 +45,8 @@ github.com/mattn/go-localereader v0.0.1/go.mod h1:8fBrzywKY7BI3czFoHkuzRoWE9C+Ei
 github.com/mattn/go-runewidth v0.0.12/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
 github.com/mattn/go-runewidth v0.0.16 h1:E5ScNMtiwvlvB5paMFdw9p4kSQzbXFikJ5SQO6TULQc=
 github.com/mattn/go-runewidth v0.0.16/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/mixpanel/mixpanel-go v1.2.1 h1:iykbHKomTJjVoWU95Vt1sjZy4HLt8UOYacMEEEMFBok=
+github.com/mixpanel/mixpanel-go v1.2.1/go.mod h1:mPGaNhBoZMJuLu8k7Y1KhU5n8Vw13rxQZZjHj+b9RLk=
 github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 h1:ZK8zHtRHOkbHy6Mmr5D264iyp3TiX5OmNcI5cIARiQI=
 github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6/go.mod h1:CJlz5H+gyd6CUWT45Oy4q24RdLyn7Md9Vj2/ldJBSIo=
 github.com/muesli/cancelreader v0.2.2 h1:3I4Kt4BQjOR54NavqnDogx/MIoWBFa0StPA8ELUXHmA=
@@ -53,6 +57,8 @@ github.com/muesli/termenv v0.16.0 h1:S5AlUN9dENB57rsbnkPyfdGuWIlkmzJjbFf0Tf5FWUc
 github.com/muesli/termenv v0.16.0/go.mod h1:ZRfOIKPFDYQoDFF4Olj7/QJbW60Ol/kL1pU3VfY/Cnk=
 github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4=
 github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
@@ -62,6 +68,8 @@ github.com/spf13/cobra v1.8.0 h1:7aJaZx1B85qltLMc546zn58BxxfZdR/W22ej9CFoEf0=
 github.com/spf13/cobra v1.8.0/go.mod h1:WXLWApfZ71AjXPya3WOlMsY9yMs7YeiHhFVlvLyhcho=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
+github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e h1:JVG44RsyaB9T2KIHavMF/ppJZNG9ZpyihvCd0w101no=
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
 golang.design/x/clipboard v0.7.1 h1:OEG3CmcYRBNnRwpDp7+uWLiZi3hrMRJpE9JkkkYtz2c=

internal/analytics/analytics.go

@@ -3,7 +3,7 @@
 // Callers depend only on the Analytics interface, so the rest of the codebase
 // never imports a concrete SDK. Two implementations are provided:
 //
-//   - MixpanelAnalytics  sends events via the Mixpanel HTTP API.
+//   - MixpanelAnalytics  sends events via the official Mixpanel Go SDK.
 //   - StdoutAnalytics    prints events to stdout as JSON for local / CI use.
 //
 // The factory New() picks between them based on whether a build-time token is
@@ -17,7 +17,7 @@ import (
 	"io"
 	"os"
 
-	"github.com/dukex/mixpanel"
+	mixpanel "github.com/mixpanel/mixpanel-go"
 )
 
 // Analytics is the single entry point for emitting a usage event. A nil
@@ -52,31 +52,30 @@ func (s StdoutAnalytics) Send(event string, properties map[string]any) error {
 	return nil
 }
 
-// MixpanelAnalytics sends events to the Mixpanel HTTP API via the dukex/mixpanel
-// SDK. It uses a distinctID of "anonymous" because reposcan does not have a
-// persistent user identity (that is handled in the telemetry layer built on
-// top of this).
+// MixpanelAnalytics sends events to the Mixpanel HTTP API via the official
+// mixpanel/mixpanel-go SDK. It uses a distinctID of "anonymous" because
+// reposcan does not have a persistent user identity (that is handled in the
+// telemetry layer built on top of this).
 type MixpanelAnalytics struct {
-	client     mixpanel.Mixpanel
+	client     *mixpanel.ApiClient
 	distinctID string
 }
 
 // NewMixpanelAnalytics constructs a live client against the Mixpanel API.
 // The token is required; passing an empty token is a caller bug.
 func NewMixpanelAnalytics(token string) *MixpanelAnalytics {
 	return &MixpanelAnalytics{
-		client:     mixpanel.New(token, ""),
+		client:     mixpanel.NewApiClient(token),
 		distinctID: "anonymous",
 	}
 }
 
 // Send forwards the event to Mixpanel. Failures are returned to the caller
-// verbatim — it is the caller's responsibility to decide whether telemetry
+// verbatim - it is the caller's responsibility to decide whether telemetry
 // failures should be logged or swallowed.
 func (m *MixpanelAnalytics) Send(event string, properties map[string]any) error {
-	if err := m.client.Track(m.distinctID, event, &mixpanel.Event{
-		Properties: properties,
-	}); err != nil {
+	ev := m.client.NewEvent(event, m.distinctID, properties)
+	if err := m.client.Track(context.Background(), []*mixpanel.Event{ev}); err != nil {
 		return fmt.Errorf("analytics: mixpanel track: %w", err)
 	}
 	return nil
@@ -90,7 +89,7 @@ var (
 
 // New picks the implementation based on build- and run-time inputs.
 //
-//   - If debug is true, events go to stdout — even when a real token is wired
+//   - If debug is true, events go to stdout - even when a real token is wired
 //     in. This keeps local development loops noisy and predictable and mirrors
 //     the behavior expected by CI harnesses.
 //   - If token is empty (a local dev build without the -ldflags injection),
@@ -103,8 +102,3 @@ func New(token string, debug bool) Analytics {
 	}
 	return NewMixpanelAnalytics(token)
 }
-
-// Context is accepted only to make the callsite forward-compatible with a
-// future version that supports cancellation and timeouts. The current
-// Mixpanel SDK ignores it; telemetry issue will plumb it through.
-var _ = context.Background

internal/analytics/analytics_test.go

@@ -87,13 +87,3 @@ func TestNew_TokenAndNoDebugReturnsMixpanel(t *testing.T) {
 	}
 }
 
-func TestAnalytics_InterfaceIsSatisfied(t *testing.T) {
-	// Compile-time: confirm both implementations satisfy the interface.
-	// The var declarations at the bottom of analytics.go already assert
-	// this, so this test is a belt-and-suspenders check that the tests
-	// import the package correctly.
-	var a Analytics
-	a = StdoutAnalytics{}
-	a = NewMixpanelAnalytics("x")
-	_ = a
-}