refactor(tests): Replace assert with require for guard assertions (#46913)

### What does this PR do?

Replaces `if !assert.XXX(...) { return }` guard patterns with `require.XXX(...)` across test files.

The testify PR stretchr/testify#1481 (merged June 2024, included in testify v1.11.1) made `require` work safely with `*assert.CollectT` inside `EventuallyWithT` callbacks. `CollectT.FailNow()` calls `runtime.Goexit()` which exits the callback goroutine — this is caught by the `EventuallyWithT` retry loop, so the test continues retrying as expected.

**Changes across 31 test files (~115 replacements):**
- `test/new-e2e/tests/containers/` — `base_test.go`, `ecs_test.go`, `k8s_test.go`
- `test/new-e2e/tests/` — `discovery/`, `agent-runtimes/`, `cspm/`, `cws/`, `npm/`, `netpath/`, `remote-config/`, `windows/`, `agent-health/`, `agent-log-pipelines/`
- `pkg/network/tracer/`, `pkg/dyninst/`, `pkg/util/`, `comp/core/telemetry/`, etc.
- Also removed outdated `// Can be replaced by require... once PR #1481 is merged` comments

### Important: `require` must not be used inside raw goroutines

While `require` is safe inside `EventuallyWithT` callbacks (thanks to `CollectT.FailNow()` integration), it must **not** be used inside raw `go func()` blocks or HTTP handler callbacks.

[`t.FailNow()`](https://pkg.go.dev/testing#T.FailNow) calls `runtime.Goexit()` to stop the current goroutine. The [official Go `testing` documentation](https://pkg.go.dev/testing#T.FailNow) states:

> FailNow must be called from the goroutine running the test or benchmark function, not from other goroutines created during the test.

`EventuallyWithT` is a special case: testify [runs the condition via `go checkCond()`](https://github.com/stretchr/testify/blob/v1.11.1/assert/assertions.go#L2108), but `CollectT` implements its own `FailNow()` that safely exits the callback goroutine and lets the retry loop continue.

**Not converted** (intentionally left as `assert`):
- Assertions inside raw `go func()` blocks (e.g., `pkg/util/winutil/eventlog/` tests)
- Callbacks/predicates returning `bool` or `error` (not test flow control)
- Bodies that only log debug info without returning

### Motivation

Using `assert` as a guard is error-prone: if someone forgets the `if !... { return }` wrapper, the test continues and panics when accessing nil/empty results (e.g., `metrics[len(metrics)-1]` on an empty slice). `require` makes the "stop on failure" intent explicit and eliminates the boilerplate.

### Describe how you validated your changes

- Verified `require` works correctly inside `EventuallyWithT` callbacks (via `CollectT.FailNow()` → `runtime.Goexit()` caught by retry loop)
- Confirmed raw `go func()` call sites were left unchanged
- These are mechanical replacements that preserve the exact same test semantics — `require` stops execution on failure, which is exactly what the `if !assert... { return }` pattern was doing manually

### Additional Notes

The remaining `if !assert` occurrences across other files were reviewed and intentionally kept because they serve different purposes (returning values from helper functions, setting flags, logging diagnostics without stopping, running inside raw goroutines, etc.).

Co-authored-by: nicolas.schweitzer <nicolas.schweitzer@datadoghq.com>

Author: chouetz

comp/core/telemetry/telemetryimpl/prom_counter_test.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestPromCounterInitializer(t *testing.T) {
@@ -41,18 +42,12 @@ func TestPromCounterInitializer(t *testing.T) {
 	counter.InitializeToZero("mycheck", "mystate")
 
 	endMetrics, err := promTelemetry.Gather()
-	if !assert.NoError(t, err) {
-		return
-	}
+	require.NoError(t, err)
 
-	if !assert.Equal(t, len(endMetrics), 1) {
-		return
-	}
+	require.Len(t, endMetrics, 1)
 
 	metricFamily := endMetrics[0]
-	if !assert.Equal(t, len(metricFamily.GetMetric()), 1) {
-		return
-	}
+	require.Len(t, metricFamily.GetMetric(), 1)
 
 	assert.Equal(t, metricFamily.GetName(), "subsystem_test")
 

comp/core/telemetry/telemetryimpl/telemetry_test.go

@@ -24,13 +24,9 @@ func TestCounterInitializer(t *testing.T) {
 	counter.InitializeToZero("mycheck", "mystate")
 
 	startMetrics, err := telemetry.GetRegistry().Gather()
-	if !assert.NoError(t, err) {
-		return
-	}
+	require.NoError(t, err)
 
-	if !assert.Equal(t, len(startMetrics), 1) {
-		return
-	}
+	require.Equal(t, len(startMetrics), 1)
 
 	metrics, err := telemetry.GetCountMetric("subsystem", "test")
 	assert.NoError(t, err)

comp/core/workloadmeta/collectors/internal/process/process_collector_test.go

@@ -18,6 +18,7 @@ import (
 	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
 	"go.uber.org/fx"
 
 	"github.com/DataDog/datadog-agent/comp/core/config"
@@ -692,9 +693,8 @@ func TestProcessDifferentCmdline(t *testing.T) {
 	// Wait for first collection to complete
 	assert.EventuallyWithT(t, func(cT *assert.CollectT) {
 		actualProc, err := c.mockStore.GetProcess(pid)
-		if !assert.NoError(cT, err) || !assert.NotNil(cT, actualProc) {
-			return
-		}
+		require.NoError(cT, err)
+		require.NotNil(cT, actualProc)
 		assert.Equal(cT, []string{"bash"}, actualProc.Cmdline)
 	}, time.Second, time.Millisecond*100)
 
@@ -704,9 +704,8 @@ func TestProcessDifferentCmdline(t *testing.T) {
 	// After exec, the store should have htop, not bash
 	assert.EventuallyWithT(t, func(cT *assert.CollectT) {
 		actualProc, err := c.mockStore.GetProcess(pid)
-		if !assert.NoError(cT, err) || !assert.NotNil(cT, actualProc) {
-			return
-		}
+		require.NoError(cT, err)
+		require.NotNil(cT, actualProc)
 		// Critical assertion: cmdline should be updated to htop after exec
 		assert.Equal(cT, []string{"htop"}, actualProc.Cmdline, "Process cmdline should be updated after exec")
 		assert.Equal(cT, "htop", actualProc.Name, "Process name should be updated after exec")

pkg/collector/check/stats/stats_test.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/DataDog/datadog-agent/comp/core/telemetry/telemetryimpl"
 	healthplatformmock "github.com/DataDog/datadog-agent/comp/healthplatform/mock"
@@ -95,9 +96,7 @@ func TestNewStatsStateTelemetryInitialized(t *testing.T) {
 	NewStats(newMockCheck(), healthplatformmock.Mock(t))
 
 	tlmData, err := getTelemetryData()
-	if !assert.NoError(t, err) {
-		return
-	}
+	require.NoError(t, err)
 
 	assert.Contains(
 		t,

pkg/collector/corechecks/gpu/integrationtests/check_test.go

@@ -82,9 +82,8 @@ func assertMetricCase(t *testing.T, metricsByName map[string][]mock.Call, tc met
 	t.Helper()
 
 	calls, ok := metricsByName[tc.name]
-	if !assert.True(t, ok, "%s metric should be present", tc.name) || !assert.NotEmpty(t, calls, "No calls found for metric %s", tc.name) {
-		return
-	}
+	require.True(t, ok, "%s metric should be present", tc.name)
+	require.NotEmpty(t, calls, "No calls found for metric %s", tc.name)
 
 	for _, call := range calls {
 		value := call.Arguments[1].(float64)

pkg/compliance/dbconfig/loader_test.go

@@ -20,6 +20,7 @@ import (
 	"github.com/DataDog/datadog-agent/pkg/compliance/types"
 	"github.com/shirou/gopsutil/v4/process"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestDBConfLoader(t *testing.T) {
@@ -599,9 +600,7 @@ include_dir 'conf.d'
 	defer stop()
 
 	c, ok := LoadPostgreSQLConfig(context.Background(), hostroot, proc)
-	if !assert.True(t, ok) {
-		return
-	}
+	require.True(t, ok)
 
 	configData := c.ConfigData.(map[string]string)
 	assert.Equal(t, "100", configData["max_connections"])
@@ -665,9 +664,7 @@ work_mem = 16MB
 
 		c, ok := LoadPostgreSQLConfig(context.Background(), hostroot, proc)
 		assert.True(t, ok)
-		if !assert.NotNil(t, c) {
-			return
-		}
+		require.NotNil(t, c)
 
 		configData := c.ConfigData.(map[string]string)
 		assert.Equal(t, "200", configData["max_connections"])
@@ -698,9 +695,7 @@ include 'circular.conf'
 
 		c, ok := LoadPostgreSQLConfig(context.Background(), hostroot, proc)
 		assert.True(t, ok)
-		if !assert.NotNil(t, c) {
-			return
-		}
+		require.NotNil(t, c)
 		// Should not crash, circular protection should kick in
 		configData := c.ConfigData.(map[string]string)
 		assert.Equal(t, "100", configData["max_connections"])

pkg/dyninst/end_to_end_test.go

@@ -306,14 +306,12 @@ func runE2ETest(t *testing.T, cfg e2eTestConfig) {
 		makeTargetStatus(uploader.StatusEmitting, expectedProbeIDs...),
 	)
 
-	assertModuleStats := func(t assert.TestingT, expected actuator.Metrics) {
+	assertModuleStats := func(t require.TestingT, expected actuator.Metrics) {
 		stats := ts.module.GetStats()["actuator"].(map[string]any)
 		exp := expected.AsStats()
 		gotKeys := slices.Sorted(maps.Keys(stats))
 		expectedKeys := slices.Sorted(maps.Keys(exp))
-		if !assert.Equal(t, gotKeys, expectedKeys) {
-			return
-		}
+		require.Equal(t, gotKeys, expectedKeys)
 		for _, key := range gotKeys {
 			assert.Equal(t, exp[key], stats[key], "key %s", key)
 		}

pkg/dyninst/missing_type_recompilation_test.go

@@ -177,9 +177,7 @@ func TestMissingTypeRecompilation(t *testing.T) {
 		require.EventuallyWithT(t, func(c *assert.CollectT) {
 			stats := m.GetStats()
 			actuatorStats, ok := stats["actuator"].(map[string]any)
-			if !assert.True(c, ok, "actuator stats missing") {
-				return
-			}
+			require.True(c, ok, "actuator stats missing")
 			assert.Equal(c, uint64(0), actuatorStats["numPrograms"],
 				"expected numPrograms == 0 after cleanup")
 			assert.Equal(c, uint64(0), actuatorStats["numProcesses"],

pkg/dyninst/procsubscribe/procscan/proc_stat_reader_test.go

@@ -19,7 +19,6 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -95,28 +94,18 @@ func testCases(t testing.TB) iter.Seq[testCase] {
 			filename := filepath.Base(entry)
 			name := strings.TrimSuffix(filename, ".txt")
 			expected, ok := expectedValues[name]
-			if !assert.True(t, ok,
-				"test file %s found but no expected values defined", name,
-			) {
-				return
-			}
+			require.True(t, ok,
+				"test file %s found but no expected values defined", name)
 			delete(expectedValues, name)
 			data, err := testdataFS.ReadFile(entry)
-			if !assert.NoError(t, err, "failed to read test data") {
-				return
-			}
+			require.NoError(t, err, "failed to read test data")
 			procRoot := filepath.Join(tempDir, name, "proc")
 			pidDir := filepath.Join(procRoot, strconv.FormatInt(int64(expected.pid), 10))
-			if !assert.NoError(t, os.MkdirAll(pidDir, 0o755)) {
-				return
-			}
+			require.NoError(t, os.MkdirAll(pidDir, 0o755))
 			statPath := filepath.Join(pidDir, "stat")
-			if !assert.NoError(
+			require.NoError(
 				t,
-				os.WriteFile(statPath, data, 0o644),
-			) {
-				return
-			}
+				os.WriteFile(statPath, data, 0o644))
 			if !yield(testCase{
 				name:     name,
 				expected: expected,

pkg/fleet/installer/setup/config/write_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"golang.org/x/text/encoding"
 	"golang.org/x/text/encoding/unicode"
 )
@@ -362,9 +363,7 @@ api_key: newkey
 		// The config file may be UTF-16 on Windows
 		t.Run(tc.name+" (UTF-16)", func(t *testing.T) {
 			encoded, err := unicode.UTF16(unicode.LittleEndian, unicode.ExpectBOM).NewEncoder().String(tc.initialYAML)
-			if !assert.NoError(t, err) {
-				return
-			}
+			require.NoError(t, err)
 			tc.initialYAML = encoded
 			runWriteConfigTestCase(t, tc)
 		})
@@ -425,14 +424,10 @@ func TestEnsureUTF8(t *testing.T) {
 	for _, e := range encodings {
 		// encode input to new encoding
 		encoded, err := e.NewEncoder().Bytes(input)
-		if !assert.NoError(t, err) {
-			return
-		}
+		require.NoError(t, err)
 		// convert it back to UTF-8
 		output, err := ensureUTF8(encoded)
-		if !assert.NoError(t, err) {
-			return
-		}
+		require.NoError(t, err)
 		assert.Equal(t, input, output)
 		// assert output does not contain BOM
 		assert.False(t, bytes.HasPrefix(output, []byte{0xFF, 0xFE}), "output should not have UTF-16LE BOM")