chore: Refactor agent tests to avoid t.Run when not needed (#5376)

It turns out that writing tests that contain subtests should probably be
limited to table-based tests and tests that share a common setup shared
between tests.

Writing tests with a subtest like this:

```
func TestSomething(t *testing.T) {
	t.Run("Subtest", func(t *testing.t) {})
}
```

Has the following disadvantages:

- It can lead to multiple tests failing with `(unknown)` status when
  only one of the subtests hang (never exit)
- In Go 1.20rc1, using `t.Setenv` is no longer allowed if the parent
  test is parallel

agent/apphealth_test.go

@@ -19,148 +19,145 @@ import (
 	"github.com/coder/coder/testutil"
 )
 
-func TestAppHealth(t *testing.T) {
+func TestAppHealth_Healthy(t *testing.T) {
 	t.Parallel()
-	t.Run("Healthy", func(t *testing.T) {
-		t.Parallel()
-		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
-		defer cancel()
-		apps := []codersdk.WorkspaceApp{
-			{
-				Slug:        "app1",
-				Healthcheck: codersdk.Healthcheck{},
-				Health:      codersdk.WorkspaceAppHealthDisabled,
+	ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
+	defer cancel()
+	apps := []codersdk.WorkspaceApp{
+		{
+			Slug:        "app1",
+			Healthcheck: codersdk.Healthcheck{},
+			Health:      codersdk.WorkspaceAppHealthDisabled,
+		},
+		{
+			Slug: "app2",
+			Healthcheck: codersdk.Healthcheck{
+				// URL: We don't set the URL for this test because the setup will
+				// create a httptest server for us and set it for us.
+				Interval:  1,
+				Threshold: 1,
 			},
-			{
-				Slug: "app2",
-				Healthcheck: codersdk.Healthcheck{
-					// URL: We don't set the URL for this test because the setup will
-					// create a httptest server for us and set it for us.
-					Interval:  1,
-					Threshold: 1,
-				},
-				Health: codersdk.WorkspaceAppHealthInitializing,
-			},
-		}
-		handlers := []http.Handler{
-			nil,
-			http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				httpapi.Write(r.Context(), w, http.StatusOK, nil)
-			}),
-		}
-		getApps, closeFn := setupAppReporter(ctx, t, apps, handlers)
-		defer closeFn()
+			Health: codersdk.WorkspaceAppHealthInitializing,
+		},
+	}
+	handlers := []http.Handler{
+		nil,
+		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			httpapi.Write(r.Context(), w, http.StatusOK, nil)
+		}),
+	}
+	getApps, closeFn := setupAppReporter(ctx, t, apps, handlers)
+	defer closeFn()
+	apps, err := getApps(ctx)
+	require.NoError(t, err)
+	require.EqualValues(t, codersdk.WorkspaceAppHealthDisabled, apps[0].Health)
+	require.Eventually(t, func() bool {
 		apps, err := getApps(ctx)
-		require.NoError(t, err)
-		require.EqualValues(t, codersdk.WorkspaceAppHealthDisabled, apps[0].Health)
-		require.Eventually(t, func() bool {
-			apps, err := getApps(ctx)
-			if err != nil {
-				return false
-			}
+		if err != nil {
+			return false
+		}
 
-			return apps[1].Health == codersdk.WorkspaceAppHealthHealthy
-		}, testutil.WaitLong, testutil.IntervalSlow)
-	})
+		return apps[1].Health == codersdk.WorkspaceAppHealthHealthy
+	}, testutil.WaitLong, testutil.IntervalSlow)
+}
 
-	t.Run("500", func(t *testing.T) {
-		t.Parallel()
-		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
-		defer cancel()
-		apps := []codersdk.WorkspaceApp{
-			{
-				Slug: "app2",
-				Healthcheck: codersdk.Healthcheck{
-					// URL: We don't set the URL for this test because the setup will
-					// create a httptest server for us and set it for us.
-					Interval:  1,
-					Threshold: 1,
-				},
-				Health: codersdk.WorkspaceAppHealthInitializing,
+func TestAppHealth_500(t *testing.T) {
+	t.Parallel()
+	ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
+	defer cancel()
+	apps := []codersdk.WorkspaceApp{
+		{
+			Slug: "app2",
+			Healthcheck: codersdk.Healthcheck{
+				// URL: We don't set the URL for this test because the setup will
+				// create a httptest server for us and set it for us.
+				Interval:  1,
+				Threshold: 1,
 			},
+			Health: codersdk.WorkspaceAppHealthInitializing,
+		},
+	}
+	handlers := []http.Handler{
+		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			httpapi.Write(r.Context(), w, http.StatusInternalServerError, nil)
+		}),
+	}
+	getApps, closeFn := setupAppReporter(ctx, t, apps, handlers)
+	defer closeFn()
+	require.Eventually(t, func() bool {
+		apps, err := getApps(ctx)
+		if err != nil {
+			return false
 		}
-		handlers := []http.Handler{
-			http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				httpapi.Write(r.Context(), w, http.StatusInternalServerError, nil)
-			}),
-		}
-		getApps, closeFn := setupAppReporter(ctx, t, apps, handlers)
-		defer closeFn()
-		require.Eventually(t, func() bool {
-			apps, err := getApps(ctx)
-			if err != nil {
-				return false
-			}
 
-			return apps[0].Health == codersdk.WorkspaceAppHealthUnhealthy
-		}, testutil.WaitLong, testutil.IntervalSlow)
-	})
+		return apps[0].Health == codersdk.WorkspaceAppHealthUnhealthy
+	}, testutil.WaitLong, testutil.IntervalSlow)
+}
 
-	t.Run("Timeout", func(t *testing.T) {
-		t.Parallel()
-		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
-		defer cancel()
-		apps := []codersdk.WorkspaceApp{
-			{
-				Slug: "app2",
-				Healthcheck: codersdk.Healthcheck{
-					// URL: We don't set the URL for this test because the setup will
-					// create a httptest server for us and set it for us.
-					Interval:  1,
-					Threshold: 1,
-				},
-				Health: codersdk.WorkspaceAppHealthInitializing,
+func TestAppHealth_Timeout(t *testing.T) {
+	t.Parallel()
+	ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
+	defer cancel()
+	apps := []codersdk.WorkspaceApp{
+		{
+			Slug: "app2",
+			Healthcheck: codersdk.Healthcheck{
+				// URL: We don't set the URL for this test because the setup will
+				// create a httptest server for us and set it for us.
+				Interval:  1,
+				Threshold: 1,
 			},
+			Health: codersdk.WorkspaceAppHealthInitializing,
+		},
+	}
+	handlers := []http.Handler{
+		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// sleep longer than the interval to cause the health check to time out
+			time.Sleep(2 * time.Second)
+			httpapi.Write(r.Context(), w, http.StatusOK, nil)
+		}),
+	}
+	getApps, closeFn := setupAppReporter(ctx, t, apps, handlers)
+	defer closeFn()
+	require.Eventually(t, func() bool {
+		apps, err := getApps(ctx)
+		if err != nil {
+			return false
 		}
-		handlers := []http.Handler{
-			http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				// sleep longer than the interval to cause the health check to time out
-				time.Sleep(2 * time.Second)
-				httpapi.Write(r.Context(), w, http.StatusOK, nil)
-			}),
-		}
-		getApps, closeFn := setupAppReporter(ctx, t, apps, handlers)
-		defer closeFn()
-		require.Eventually(t, func() bool {
-			apps, err := getApps(ctx)
-			if err != nil {
-				return false
-			}
 
-			return apps[0].Health == codersdk.WorkspaceAppHealthUnhealthy
-		}, testutil.WaitLong, testutil.IntervalSlow)
-	})
+		return apps[0].Health == codersdk.WorkspaceAppHealthUnhealthy
+	}, testutil.WaitLong, testutil.IntervalSlow)
+}
 
-	t.Run("NotSpamming", func(t *testing.T) {
-		t.Parallel()
-		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
-		defer cancel()
-		apps := []codersdk.WorkspaceApp{
-			{
-				Slug: "app2",
-				Healthcheck: codersdk.Healthcheck{
-					// URL: We don't set the URL for this test because the setup will
-					// create a httptest server for us and set it for us.
-					Interval:  1,
-					Threshold: 1,
-				},
-				Health: codersdk.WorkspaceAppHealthInitializing,
+func TestAppHealth_NotSpamming(t *testing.T) {
+	t.Parallel()
+	ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
+	defer cancel()
+	apps := []codersdk.WorkspaceApp{
+		{
+			Slug: "app2",
+			Healthcheck: codersdk.Healthcheck{
+				// URL: We don't set the URL for this test because the setup will
+				// create a httptest server for us and set it for us.
+				Interval:  1,
+				Threshold: 1,
 			},
-		}
+			Health: codersdk.WorkspaceAppHealthInitializing,
+		},
+	}
 
-		var counter = new(int32)
-		handlers := []http.Handler{
-			http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				atomic.AddInt32(counter, 1)
-			}),
-		}
-		_, closeFn := setupAppReporter(ctx, t, apps, handlers)
-		defer closeFn()
-		// Ensure we haven't made more than 2 (expected 1 + 1 for buffer) requests in the last second.
-		// if there is a bug where we are spamming the healthcheck route this will catch it.
-		time.Sleep(time.Second)
-		require.LessOrEqual(t, *counter, int32(2))
-	})
+	counter := new(int32)
+	handlers := []http.Handler{
+		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			atomic.AddInt32(counter, 1)
+		}),
+	}
+	_, closeFn := setupAppReporter(ctx, t, apps, handlers)
+	defer closeFn()
+	// Ensure we haven't made more than 2 (expected 1 + 1 for buffer) requests in the last second.
+	// if there is a bug where we are spamming the healthcheck route this will catch it.
+	time.Sleep(time.Second)
+	require.LessOrEqual(t, *counter, int32(2))
 }
 
 func setupAppReporter(ctx context.Context, t *testing.T, apps []codersdk.WorkspaceApp, handlers []http.Handler) (agent.WorkspaceAgentApps, func()) {