fix(coderd): avoid fetching extra parameters for a preset (coder#16642)

This pull request fixes a bug in presets and adds tests to ensure it
doesn't happen again.
Due to an oversight in refactoring, we returned extra and incorrect
parameters from other presets in the same template version when calling
`/templateversions/{templateversion}/presets`.

Author: SasSwart

coderd/presets.go

@@ -45,6 +45,10 @@ func (api *API) templateVersionPresets(rw http.ResponseWriter, r *http.Request)
 			Name: preset.Name,
 		}
 		for _, presetParam := range presetParams {
+			if presetParam.TemplateVersionPresetID != preset.ID {
+				continue
+			}
+
 			sdkPreset.Parameters = append(sdkPreset.Parameters, codersdk.PresetParameter{
 				Name:  presetParam.Name,
 				Value: presetParam.Value,

coderd/presets_test.go

@@ -17,58 +17,128 @@ import (
 func TestTemplateVersionPresets(t *testing.T) {
 	t.Parallel()
 
-	givenPreset := codersdk.Preset{
-		Name: "My Preset",
-		Parameters: []codersdk.PresetParameter{
-			{
-				Name:  "preset_param1",
-				Value: "A1B2C3",
+	testCases := []struct {
+		name    string
+		presets []codersdk.Preset
+	}{
+		{
+			name:    "no presets",
+			presets: []codersdk.Preset{},
+		},
+		{
+			name: "single preset with parameters",
+			presets: []codersdk.Preset{
+				{
+					Name: "My Preset",
+					Parameters: []codersdk.PresetParameter{
+						{
+							Name:  "preset_param1",
+							Value: "A1B2C3",
+						},
+						{
+							Name:  "preset_param2",
+							Value: "D4E5F6",
+						},
+					},
+				},
 			},
-			{
-				Name:  "preset_param2",
-				Value: "D4E5F6",
+		},
+		{
+			name: "multiple presets with overlapping parameters",
+			presets: []codersdk.Preset{
+				{
+					Name: "Preset 1",
+					Parameters: []codersdk.PresetParameter{
+						{
+							Name:  "shared_param",
+							Value: "value1",
+						},
+						{
+							Name:  "unique_param1",
+							Value: "unique1",
+						},
+					},
+				},
+				{
+					Name: "Preset 2",
+					Parameters: []codersdk.PresetParameter{
+						{
+							Name:  "shared_param",
+							Value: "value2",
+						},
+						{
+							Name:  "unique_param2",
+							Value: "unique2",
+						},
+					},
+				},
 			},
 		},
 	}
-	ctx := testutil.Context(t, testutil.WaitShort)
 
-	client, db := coderdtest.NewWithDatabase(t, &coderdtest.Options{IncludeProvisionerDaemon: true})
-	user := coderdtest.CreateFirstUser(t, client)
-	version := coderdtest.CreateTemplateVersion(t, client, user.OrganizationID, nil)
+	for _, tc := range testCases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			ctx := testutil.Context(t, testutil.WaitShort)
 
-	// nolint:gocritic // This is a test
-	provisionerCtx := dbauthz.AsProvisionerd(ctx)
+			client, db := coderdtest.NewWithDatabase(t, &coderdtest.Options{IncludeProvisionerDaemon: true})
+			user := coderdtest.CreateFirstUser(t, client)
+			version := coderdtest.CreateTemplateVersion(t, client, user.OrganizationID, nil)
 
-	dbPreset, err := db.InsertPreset(provisionerCtx, database.InsertPresetParams{
-		Name:              givenPreset.Name,
-		TemplateVersionID: version.ID,
-	})
-	require.NoError(t, err)
+			// nolint:gocritic // This is a test
+			provisionerCtx := dbauthz.AsProvisionerd(ctx)
 
-	var presetParameterNames []string
-	var presetParameterValues []string
-	for _, presetParameter := range givenPreset.Parameters {
-		presetParameterNames = append(presetParameterNames, presetParameter.Name)
-		presetParameterValues = append(presetParameterValues, presetParameter.Value)
-	}
-	_, err = db.InsertPresetParameters(provisionerCtx, database.InsertPresetParametersParams{
-		TemplateVersionPresetID: dbPreset.ID,
-		Names:                   presetParameterNames,
-		Values:                  presetParameterValues,
-	})
-	require.NoError(t, err)
+			// Insert all presets for this test case
+			for _, givenPreset := range tc.presets {
+				dbPreset, err := db.InsertPreset(provisionerCtx, database.InsertPresetParams{
+					Name:              givenPreset.Name,
+					TemplateVersionID: version.ID,
+				})
+				require.NoError(t, err)
+
+				if len(givenPreset.Parameters) > 0 {
+					var presetParameterNames []string
+					var presetParameterValues []string
+					for _, presetParameter := range givenPreset.Parameters {
+						presetParameterNames = append(presetParameterNames, presetParameter.Name)
+						presetParameterValues = append(presetParameterValues, presetParameter.Value)
+					}
+					_, err = db.InsertPresetParameters(provisionerCtx, database.InsertPresetParametersParams{
+						TemplateVersionPresetID: dbPreset.ID,
+						Names:                   presetParameterNames,
+						Values:                  presetParameterValues,
+					})
+					require.NoError(t, err)
+				}
+			}
+
+			userSubject, _, err := httpmw.UserRBACSubject(ctx, db, user.UserID, rbac.ScopeAll)
+			require.NoError(t, err)
+			userCtx := dbauthz.As(ctx, userSubject)
 
-	userSubject, _, err := httpmw.UserRBACSubject(ctx, db, user.UserID, rbac.ScopeAll)
-	require.NoError(t, err)
-	userCtx := dbauthz.As(ctx, userSubject)
+			gotPresets, err := client.TemplateVersionPresets(userCtx, version.ID)
+			require.NoError(t, err)
 
-	gotPresets, err := client.TemplateVersionPresets(userCtx, version.ID)
-	require.NoError(t, err)
+			require.Equal(t, len(tc.presets), len(gotPresets))
 
-	require.Equal(t, 1, len(gotPresets))
-	require.Equal(t, givenPreset.Name, gotPresets[0].Name)
+			for _, expectedPreset := range tc.presets {
+				found := false
+				for _, gotPreset := range gotPresets {
+					if gotPreset.Name == expectedPreset.Name {
+						found = true
 
-	for _, presetParameter := range givenPreset.Parameters {
-		require.Contains(t, gotPresets[0].Parameters, presetParameter)
+						// verify not only that we get the right number of parameters, but that we get the right parameters
+						// This ensures that we don't get extra parameters from other presets
+						require.Equal(t, len(expectedPreset.Parameters), len(gotPreset.Parameters))
+						for _, expectedParam := range expectedPreset.Parameters {
+							require.Contains(t, gotPreset.Parameters, expectedParam)
+						}
+						break
+					}
+				}
+				require.True(t, found, "Expected preset %s not found in results", expectedPreset.Name)
+			}
+		})
 	}
 }