feat: add user-level parameter autofill (#11731)

This PR solves #10478 by auto-filling previously used template values in create and update workspace flows.

I decided against explicit user values in settings for these reasons:

* Autofill is far easier to implement
* Users benefit from autofill _by default_ — we don't need to teach them new concepts
* If we decide that autofill creates more harm than good, we can remove it without breaking compatibility

coderd/users_test.go

@@ -23,6 +23,7 @@ import (
 	"github.com/coder/coder/v2/coderd/coderdtest"
 	"github.com/coder/coder/v2/coderd/database"
 	"github.com/coder/coder/v2/coderd/database/dbauthz"
+	"github.com/coder/coder/v2/coderd/database/dbfake"
 	"github.com/coder/coder/v2/coderd/database/dbgen"
 	"github.com/coder/coder/v2/coderd/database/dbtime"
 	"github.com/coder/coder/v2/coderd/rbac"
@@ -1721,6 +1722,129 @@ func TestSuspendedPagination(t *testing.T) {
 	require.Equal(t, expected, page.Users, "expected page")
 }
 
+func TestUserAutofillParameters(t *testing.T) {
+	t.Parallel()
+	t.Run("NotSelf", func(t *testing.T) {
+		t.Parallel()
+		client1, _, api := coderdtest.NewWithAPI(t, &coderdtest.Options{})
+
+		u1 := coderdtest.CreateFirstUser(t, client1)
+
+		client2, u2 := coderdtest.CreateAnotherUser(t, client1, u1.OrganizationID)
+
+		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
+		defer cancel()
+
+		db := api.Database
+
+		version := dbfake.TemplateVersion(t, db).Seed(database.TemplateVersion{
+			CreatedBy:      u1.UserID,
+			OrganizationID: u1.OrganizationID,
+		}).Params(database.TemplateVersionParameter{
+			Name:     "param",
+			Required: true,
+		}).Do()
+
+		_, err := client2.UserAutofillParameters(
+			ctx,
+			u1.UserID.String(),
+			version.Template.ID,
+		)
+
+		var apiErr *codersdk.Error
+		require.ErrorAs(t, err, &apiErr)
+		require.Equal(t, http.StatusBadRequest, apiErr.StatusCode())
+
+		// u1 should be able to read u2's parameters as u1 is site admin.
+		_, err = client1.UserAutofillParameters(
+			ctx,
+			u2.ID.String(),
+			version.Template.ID,
+		)
+		require.NoError(t, err)
+	})
+
+	t.Run("FindsParameters", func(t *testing.T) {
+		t.Parallel()
+		client1, _, api := coderdtest.NewWithAPI(t, &coderdtest.Options{})
+
+		u1 := coderdtest.CreateFirstUser(t, client1)
+
+		client2, u2 := coderdtest.CreateAnotherUser(t, client1, u1.OrganizationID)
+
+		db := api.Database
+
+		version := dbfake.TemplateVersion(t, db).Seed(database.TemplateVersion{
+			CreatedBy:      u1.UserID,
+			OrganizationID: u1.OrganizationID,
+		}).Params(database.TemplateVersionParameter{
+			Name:     "param",
+			Required: true,
+		},
+			database.TemplateVersionParameter{
+				Name:      "param2",
+				Ephemeral: true,
+			},
+		).Do()
+
+		dbfake.WorkspaceBuild(t, db, database.Workspace{
+			OwnerID:        u2.ID,
+			TemplateID:     version.Template.ID,
+			OrganizationID: u1.OrganizationID,
+		}).Params(
+			database.WorkspaceBuildParameter{
+				Name:  "param",
+				Value: "foo",
+			},
+			database.WorkspaceBuildParameter{
+				Name:  "param2",
+				Value: "bar",
+			},
+		).Do()
+
+		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
+		defer cancel()
+
+		// Use client2 since client1 is site admin, so
+		// we don't get good coverage on RBAC working.
+		params, err := client2.UserAutofillParameters(
+			ctx,
+			u2.ID.String(),
+			version.Template.ID,
+		)
+		require.NoError(t, err)
+
+		require.Equal(t, 1, len(params))
+
+		require.Equal(t, "param", params[0].Name)
+		require.Equal(t, "foo", params[0].Value)
+
+		// Verify that latest parameter value is returned.
+		dbfake.WorkspaceBuild(t, db, database.Workspace{
+			OrganizationID: u1.OrganizationID,
+			OwnerID:        u2.ID,
+			TemplateID:     version.Template.ID,
+		}).Params(
+			database.WorkspaceBuildParameter{
+				Name:  "param",
+				Value: "foo_new",
+			},
+		).Do()
+
+		params, err = client2.UserAutofillParameters(
+			ctx,
+			u2.ID.String(),
+			version.Template.ID,
+		)
+		require.NoError(t, err)
+
+		require.Equal(t, 1, len(params))
+
+		require.Equal(t, "param", params[0].Name)
+		require.Equal(t, "foo_new", params[0].Value)
+	})
+}
+
 // TestPaginatedUsers creates a list of users, then tries to paginate through
 // them using different page sizes.
 func TestPaginatedUsers(t *testing.T) {