Eliminate code duplication in test setup and service data fetching

[Copilot]

Qlty identified ~200 lines of duplicated code across test files and service classes in the air, water, soil, and traffic modules.

Changes

Test Setup Consolidation

• Created createTestingModuleWithCommonProviders() in src/common/test-helpers.ts
• Refactored 8 test files to use shared setup instead of duplicating 20+ lines each

Service Layer Abstraction

• Created BaseDataService<T> abstract class in src/common/base-data.service.ts
• Encapsulates common findOne() implementation: Supabase query, timezone validation/formatting, error handling
• Refactored AirService, WaterService, SoilService, TrafficService to extend base class

Before:

export class AirService {
  async findOne(devEui: string, startDate: Date, endDate: Date, timezone?: string) {
    const normalizedTimeZone = timezone?.trim() || null;
    if (normalizedTimeZone) {
      this.timezoneFormatter.assertValidTimeZone(normalizedTimeZone);
    }
    const { data, error } = await this.supabaseService
      .getClient()
      .from('cw_air_data')
      // ... 40+ more duplicated lines
  }
}

After:

export class AirService extends BaseDataService<'cw_air_data'> {
  constructor(supabaseService: SupabaseService, timezoneFormatter: TimezoneFormatterService) {
    super(supabaseService, timezoneFormatter, 'cw_air_data');
  }
}

Pattern applies identically to water, soil, and traffic services.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• scarf.sh
  • Triggering command: /usr/local/bin/node node ./report.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Qlty: Found 29 lines of similar code in 4 locations (mass = 159)</issue_title>
<issue_description>Issue on Qlty

Found 27 lines of similar code in 4 locations (mass = 83)
src/air/air.controller.spec.ts

import
{ Test, TestingModule }
from

'@nestjs/testing'
;
import
{ AirController }
from

'./air.controller'
;
import
{ AirService }
from

'./air.service'
;
import
{ SupabaseService }
from

'../supabase/supabase.service'
;
import
{ TimezoneFormatterService }
from

'../common/timezone-formatter.service'
;
describe(
'AirController'
,
() =>
{

let
controller: AirController;
beforeEach(
async
() => {
Found 25 lines of similar code in 4 locations (mass = 79)
src/air/air.service.spec.ts

import
{ Test, TestingModule }
from

'@nestjs/testing'
;
import
{ AirService }
from

'./air.service'
;
import
{ SupabaseService }
from

'../supabase/supabase.service'
;
import
{ TimezoneFormatterService }
from

'../common/timezone-formatter.service'
;
describe(
'AirService'
,
() =>
{

let
service: AirService;
beforeEach(
async
() => {

const

module
: TestingModule =
await
Test.createTestingModule({
Found 29 lines of similar code in 4 locations (mass = 159)
src/air/air.service.ts

devEui: 

string
,

startDate
:
Date
,

endDate
:
Date
,
timezone?:
string
,
):
Promise
<TableRow<
'cw_air_data'

[]> {

const
normalizedTimeZone = timezone?.trim() ||
null
;

if
(normalizedTimeZone) {

this
.timezoneFormatter.assertValidTimeZone(normalizedTimeZone);
}
Found 19 lines of similar code in 2 locations (mass = 71)
src/power/power.service.spec.ts

import
{ Test, TestingModule }
from

'@nestjs/testing'
;
import
{ PowerService }
from

'./power.service'
;
describe(
'PowerService'
,
() =>
{

let
service: PowerService;
beforeEach(
async
() => {

const

module
: TestingModule =
await
Test.createTestingModule({

providers
: [PowerService],
}).compile();
Found 19 lines of similar code in 2 locations (mass = 71)
src/realtime/realtime.service.spec.ts

import
{ Test, TestingModule }
from

'@nestjs/testing'
;
import
{ RealtimeService }
from

'./realtime.service'
;
describe(
'RealtimeService'
,
() =>
{

let
service: RealtimeService;
beforeEach(
async
() => {

const

module
: TestingModule =
await
Test.createTestingModule({

providers
: [RealtimeService],
}).compile();
Found 27 lines of similar code in 4 locations (mass = 83)
src/soil/soil.controller.spec.ts

import
{ Test, TestingModule }
from

'@nestjs/testing'
;
import
{ SoilController }
from

'./soil.controller'
;
import
{ SoilService }
from

'./soil.service'
;
import
{ SupabaseService }
from

'../supabase/supabase.service'
;
import
{ TimezoneFormatterService }
from

'../common/timezone-formatter.service'
;
describe(
'SoilController'
,
() =>
{

let
controller: SoilController;
beforeEach(
async
() => {
Found 90 lines of similar code in 3 locations (mass = 423)
src/soil/soil.controller.ts

import
{ BadRequestException, Controller, Get, Post, Body, Patch, Param, Delete, Query, UseGuards }
from

'@nestjs/common'
;
import
{ SoilService }
from

'./soil.service'
;
import
{ SoilDataDto }
from

'./dto/soil-data.dto'
;
import

type
{ CreateSoilDto }
from

'./dto/create-soil.dto'
;
import

type
{ UpdateSoilDto }
from

'./dto/update-soil.dto'
;
import
{ JwtAuthGuard }
from

'../auth/guards/jwt.auth.guard'
;
import
{ ApiBadRequestResponse, ApiBearerAuth, ApiInternalServerErrorResponse, ApiOkResponse, ApiParam, ApiQuery, ApiSecurity, ApiUnauthorizedResponse }
from

'@nestjs/swagger'
;
import
{ ErrorResponseDto }
from

'../common/dto/error-response.dto'
;
@controller
(
'soil'
)
Found 25 lines of similar code in 4 locations (mass = 79)
src/soil/soil.service.spec.ts

import
{ Test, TestingModule }
from

'@nestjs/testing'
;
import
{ SoilService }
from

'./soil.service'
;
import
{ SupabaseService }
from

'../supabase/supabase.service'
;
import
{ TimezoneFormatterService...

• Fixes Qlty: Found 29 lines of similar code in 4 locations (mass = 159) #8

---

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Project	Deployment	Review	Updated (UTC)
api	Ready	Preview, Comment	Jan 20, 2026 4:59am