Add UT for Detector List page

[ohltyler]

Issue #, if available: #191

Description of changes:

This PR adds several unit tests throughout the DetectorsList/ directory to increase code coverage and handle more test cases. Below are the before/after of the code coverage.

Before:

-----------------------------------------------------------------|----------|----------|----------|----------|-------------------|
File                                                             |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
-----------------------------------------------------------------|----------|----------|----------|----------|-------------------|
 public/pages/DetectorsList/components/EmptyMessage              |      100 |      100 |      100 |      100 |                   |
  EmptyMessage.tsx                                               |      100 |      100 |      100 |      100 |                   |
 public/pages/DetectorsList/components/ListActions               |       80 |      100 |    66.67 |       80 |                   |
  ListActions.tsx                                                |       80 |      100 |    66.67 |       80 |                56 |
 public/pages/DetectorsList/components/ListFilters               |      100 |      100 |      100 |      100 |                   |
  ListFilters.tsx                                                |      100 |      100 |      100 |      100 |                   |
 public/pages/DetectorsList/containers/ConfirmActionModals       |    89.74 |    88.46 |    91.67 |    89.74 |                   |
  ConfirmDeleteDetectorsModal.tsx                                |    81.82 |    85.29 |    85.71 |    81.82 |   168,170,171,175 |
  ConfirmStartDetectorsModal.tsx                                 |      100 |      100 |      100 |      100 |                   |
  ConfirmStopDetectorsModal.tsx                                  |      100 |    91.67 |      100 |      100 |                56 |
 public/pages/DetectorsList/containers/ConfirmActionModals/utils |      100 |    91.67 |    78.57 |      100 |                   |
  helpers.tsx                                                    |      100 |    91.67 |    78.57 |      100 |               117 |
 public/pages/DetectorsList/containers/List                      |    54.04 |    38.78 |    40.74 |    55.19 |                   |
  List.tsx                                                       |    54.04 |    38.78 |    40.74 |    55.19 |... 54,565,577,590 |
 public/pages/DetectorsList/utils                                |    72.97 |    66.67 |    66.67 |    72.22 |                   |
  constants.ts                                                   |      100 |      100 |      100 |      100 |                   |
  helpers.ts                                                     |    56.52 |    60.87 |       50 |    54.55 |... 99,100,101,104 |
  tableUtils.tsx                                                 |      100 |      100 |      100 |      100

After:

-----------------------------------------------------------------|----------|----------|----------|----------|-------------------|
File                                                             |  % Stmts | % Branch |  % Funcs |  % Lines | Uncovered Line #s |
-----------------------------------------------------------------|----------|----------|----------|----------|-------------------|
 public/pages/DetectorsList/components/EmptyMessage              |      100 |      100 |      100 |      100 |                   |
  EmptyMessage.tsx                                               |      100 |      100 |      100 |      100 |                   |
 public/pages/DetectorsList/components/ListActions               |       80 |      100 |    66.67 |       80 |                   |
  ListActions.tsx                                                |       80 |      100 |    66.67 |       80 |                56 |
 public/pages/DetectorsList/components/ListFilters               |      100 |      100 |      100 |      100 |                   |
  ListFilters.tsx                                                |      100 |      100 |      100 |      100 |                   |
 public/pages/DetectorsList/containers/ConfirmActionModals       |    94.87 |    92.31 |    91.67 |    94.87 |                   |
  ConfirmDeleteDetectorsModal.tsx                                |    90.91 |    91.18 |    85.71 |    90.91 |           170,171 |
  ConfirmStartDetectorsModal.tsx                                 |      100 |      100 |      100 |      100 |                   |
  ConfirmStopDetectorsModal.tsx                                  |      100 |    91.67 |      100 |      100 |                56 |
 public/pages/DetectorsList/containers/ConfirmActionModals/utils |      100 |    91.67 |    78.57 |      100 |                   |
  helpers.tsx                                                    |      100 |    91.67 |    78.57 |      100 |               117 |
 public/pages/DetectorsList/containers/List                      |    63.35 |    53.06 |     46.3 |    64.94 |                   |
  List.tsx                                                       |    63.35 |    53.06 |     46.3 |    64.94 |... 27,536,543,590 |
 public/pages/DetectorsList/utils                                |      100 |      100 |      100 |      100 |                   |
  constants.ts                                                   |      100 |      100 |      100 |      100 |                   |
  helpers.ts                                                     |      100 |      100 |      100 |      100 |                   |
  tableUtils.tsx                                                 |      100 |      100 |      100 |      100 |                   |

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[yizheliu-amazon]

Cool. Thanks for the change. Btw, is it possible to increase coverage for public/pages/DetectorsList/containers/List

[ohltyler]

Cool. Thanks for the change. Btw, is it possible to increase coverage for public/pages/DetectorsList/containers/List

Yeah, so I spent way too long trying to cover more test cases there, but ran into many issues with trying to keep a mock store of detectors and indices in addition to mocking http responses. Basically, the mock store cannot be dynamically changed within a test case, and the way the page currently renders is retrieve the store -> change a filter -> fetch new results from ES -> update store -> re-render page after store is updated. This is impossible to achieve since the store can't be updated, and the page gets stuck in a loading state.

As far as unit tests go, testing the page as a whole involves too many moving pieces I'd say. The parts of code that are not being covered here are being covered in the integration tests (filtering by detector state, etc.).

[yizheliu-amazon]

Cool. Thanks for the change. Btw, is it possible to increase coverage for public/pages/DetectorsList/containers/List

Yeah, so I spent way too long trying to cover more test cases there, but ran into many issues with trying to keep a mock store of detectors and indices in addition to mocking http responses. Basically, the mock store cannot be dynamically changed within a test case, and the way the page currently renders is retrieve the store -> change a filter -> fetch new results from ES -> update store -> re-render page after store is updated. This is impossible to achieve since the store can't be updated, and the page gets stuck in a loading state.

As far as unit tests go, testing the page as a whole involves too many moving pieces I'd say. The parts of code that are not being covered here are being covered in the integration tests (filtering by detector state, etc.).

Covering in IT sounds good to me.