test(sidecar): split tests across stub and withsidecar builds

Default !withsidecar build: assert IsPlaceholder, empty JAR,
Extract errors. withsidecar build: existing extract/checksum
coverage.

internal/sidecar/embed_test.go

@@ -1,95 +1,20 @@
+//go:build !withsidecar
+
 package sidecar
 
-import (
-	"crypto/sha256"
-	"encoding/hex"
-	"os"
-	"path/filepath"
-	"testing"
-)
+import "testing"
 
-func TestEmbeddedNonZero(t *testing.T) {
-	if EmbeddedSize() == 0 {
-		t.Errorf("expected embedded JAR to be non-empty")
-	}
-}
-
-func TestExtract_WritesJARAndChecksum(t *testing.T) {
-	directory := t.TempDir()
-	path, err := Extract(directory)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if path != filepath.Join(directory, "uatu-sidecar.jar") {
-		t.Errorf("unexpected path: %s", path)
-	}
-	body, err := os.ReadFile(path)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if EmbeddedSize() != len(body) {
-		t.Errorf("size mismatch: embedded=%d, written=%d", EmbeddedSize(), len(body))
-	}
-	sum := sha256.Sum256(body)
-	if hex.EncodeToString(sum[:]) != EmbeddedSHA256() {
-		t.Errorf("hash mismatch")
-	}
-	checksum, err := os.ReadFile(path + ".sha256")
-	if err != nil {
-		t.Fatal(err)
-	}
-	if string(checksum) != EmbeddedSHA256() {
-		t.Errorf("checksum file content wrong: %q", checksum)
-	}
-}
-
-func TestExtract_ReusesIdenticalFile(t *testing.T) {
-	directory := t.TempDir()
-	path, err := Extract(directory)
-	if err != nil {
-		t.Fatal(err)
-	}
-	originalStat, err := os.Stat(path)
-	if err != nil {
-		t.Fatal(err)
-	}
-	originalModTime := originalStat.ModTime()
-
-	// Second extract should be a no-op (no rewrite).
-	if _, err := Extract(directory); err != nil {
-		t.Fatal(err)
-	}
-	secondStat, err := os.Stat(path)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if !secondStat.ModTime().Equal(originalModTime) {
-		t.Errorf("second extract should not have rewritten the file")
-	}
-}
-
-func TestExtract_RewritesIfChecksumMissing(t *testing.T) {
-	directory := t.TempDir()
-	path, err := Extract(directory)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if err := os.Remove(path + ".sha256"); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := Extract(directory); err != nil {
-		t.Fatal(err)
-	}
-	if _, err := os.Stat(path + ".sha256"); err != nil {
-		t.Errorf("checksum should have been written: %v", err)
-	}
-}
-
-func TestIsPlaceholder_FlagsDevBuilds(t *testing.T) {
-	// The repo ships with a placeholder so fresh clones build without
-	// needing `make sidecar` first. The flag lets `uatu test` warn loudly
-	// before trying to drive a real device.
+func TestStub_IsPlaceholder(t *testing.T) {
 	if !IsPlaceholder() {
-		t.Logf("running against a real sidecar JAR (size=%d)", EmbeddedSize())
+		t.Errorf("default build should be a placeholder")
+	}
+	if EmbeddedSize() != 0 {
+		t.Errorf("stub should have empty embedded JAR, got size %d", EmbeddedSize())
+	}
+}
+
+func TestStub_ExtractFails(t *testing.T) {
+	if _, err := Extract(t.TempDir()); err == nil {
+		t.Fatal("expected Extract to fail in stub mode")
 	}
 }

internal/sidecar/embed_withsidecar_test.go

@@ -0,0 +1,90 @@
+//go:build withsidecar
+
+package sidecar
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestEmbeddedNonZero(t *testing.T) {
+	if EmbeddedSize() == 0 {
+		t.Errorf("expected embedded JAR to be non-empty")
+	}
+	if IsPlaceholder() {
+		t.Errorf("withsidecar build should not be a placeholder")
+	}
+}
+
+func TestExtract_WritesJARAndChecksum(t *testing.T) {
+	directory := t.TempDir()
+	path, err := Extract(directory)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if path != filepath.Join(directory, "uatu-sidecar.jar") {
+		t.Errorf("unexpected path: %s", path)
+	}
+	body, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if EmbeddedSize() != len(body) {
+		t.Errorf("size mismatch: embedded=%d, written=%d", EmbeddedSize(), len(body))
+	}
+	sum := sha256.Sum256(body)
+	if hex.EncodeToString(sum[:]) != EmbeddedSHA256() {
+		t.Errorf("hash mismatch")
+	}
+	checksum, err := os.ReadFile(path + ".sha256")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(checksum) != EmbeddedSHA256() {
+		t.Errorf("checksum file content wrong: %q", checksum)
+	}
+}
+
+func TestExtract_ReusesIdenticalFile(t *testing.T) {
+	directory := t.TempDir()
+	path, err := Extract(directory)
+	if err != nil {
+		t.Fatal(err)
+	}
+	originalStat, err := os.Stat(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	originalModTime := originalStat.ModTime()
+
+	if _, err := Extract(directory); err != nil {
+		t.Fatal(err)
+	}
+	secondStat, err := os.Stat(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !secondStat.ModTime().Equal(originalModTime) {
+		t.Errorf("second extract should not have rewritten the file")
+	}
+}
+
+func TestExtract_RewritesIfChecksumMissing(t *testing.T) {
+	directory := t.TempDir()
+	path, err := Extract(directory)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Remove(path + ".sha256"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := Extract(directory); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.Stat(path + ".sha256"); err != nil {
+		t.Errorf("checksum should have been written: %v", err)
+	}
+}