Make the end-to-end suite opt-in and a separate CI step

.github/workflows/build.yml

@@ -31,3 +31,6 @@ jobs:
 
     - name: Run pre-commit checks
       run: just pre-commit
+
+    - name: Run end-to-end tests
+      run: just test-e2e

Justfile

@@ -11,7 +11,7 @@ build-release:
     go build -ldflags="-s -w" -o http-assert .
 
 [doc("Run all pre-commit checks")]
-pre-commit: build vet lint test test-race test-cover security
+pre-commit: build vet lint test test-race security
 
 [doc("Build and check compilation without creating binary")]
 check:
@@ -25,10 +25,14 @@ vet:
 lint:
     golangci-lint run ./...
 
-[doc("Run tests")]
+[doc("Run unit tests (fast; end-to-end tests are skipped)")]
 test:
     go test ./...
 
+[doc("Run the end-to-end suite (builds and executes the CLI)")]
+test-e2e:
+    go test ./... -e2e -count=1
+
 [doc("Run tests with race detection")]
 test-race:
     go test ./... -race
@@ -43,7 +47,7 @@ test-cover:
     set -euo pipefail
     unit=$(mktemp -d); e2e=$(mktemp -d)
     trap 'rm -rf "$unit" "$e2e"' EXIT
-    E2E_COVERDIR="$e2e" go test ./... -cover -args -test.gocoverdir="$unit"
+    E2E_COVERDIR="$e2e" go test ./... -e2e -count=1 -cover -args -test.gocoverdir="$unit"
     go tool covdata percent -i="$unit,$e2e"
 
 [doc("Run tests with coverage and generate HTML report")]
@@ -52,7 +56,7 @@ test-coverage:
     set -euo pipefail
     unit=$(mktemp -d); e2e=$(mktemp -d)
     trap 'rm -rf "$unit" "$e2e"' EXIT
-    E2E_COVERDIR="$e2e" go test ./... -cover -args -test.gocoverdir="$unit"
+    E2E_COVERDIR="$e2e" go test ./... -e2e -count=1 -cover -args -test.gocoverdir="$unit"
     go tool covdata textfmt -i="$unit,$e2e" -o=coverage.out
     go tool cover -html=coverage.out -o coverage.html
     echo "Coverage report: coverage.html"
@@ -63,7 +67,7 @@ test-cover-func:
     set -euo pipefail
     unit=$(mktemp -d); e2e=$(mktemp -d)
     trap 'rm -rf "$unit" "$e2e"' EXIT
-    E2E_COVERDIR="$e2e" go test ./... -cover -args -test.gocoverdir="$unit" >/dev/null
+    E2E_COVERDIR="$e2e" go test ./... -e2e -count=1 -cover -args -test.gocoverdir="$unit" >/dev/null
     go tool covdata func -i="$unit,$e2e" | sort -k2 -n
 
 [doc("Clean build artifacts")]
@@ -87,6 +91,9 @@ deps-update:
 deps-download:
     go mod download
 
+[doc("Run every check CI runs, including the end-to-end suite")]
+pre-push: pre-commit test-e2e
+
 [doc("Run a quick development cycle")]
 dev: fmt vet test
 

e2e_harness_test.go

@@ -1,6 +1,7 @@
 package main_test
 
 import (
+	"flag"
 	"fmt"
 	"os"
 	"os/exec"
@@ -18,6 +19,15 @@ import (
 // #55 run() extraction, #56 assertion constructors), which is the property that
 // makes those refactors safe to perform.
 
+// runE2E gates the whole suite. It is opt-in: `go test ./...` runs the unit
+// tests only, and the end-to-end tests run when explicitly asked for.
+//
+// A registered flag is used rather than a build tag on purpose. A tagged file
+// is invisible to `go vet` and `golangci-lint` unless every invocation passes
+// the tag, so tagging would silently drop this file out of both -- verified,
+// and the reason the switch lives here instead.
+var runE2E = flag.Bool("e2e", false, "run the end-to-end suite (builds and executes the CLI)")
+
 var (
 	binPath  string
 	buildErr error
@@ -35,6 +45,10 @@ func coverDir() string { return os.Getenv("E2E_COVERDIR") }
 func binary(t *testing.T) string {
 	t.Helper()
 
+	if !*runE2E {
+		t.Skip("e2e: pass -e2e to run (or use `just test-e2e`)")
+	}
+
 	buildOne.Do(func() {
 		dir, err := os.MkdirTemp("", "http-assert-e2e")
 		if err != nil {