Before:
  function Range(start_line, start_char, end_line, end_char) abort
    return {
    \ 'start': {'line': a:start_line, 'character': a:start_char},
    \ 'end': {'line': a:end_line, 'character': a:end_char},
    \}
  endfunction

After:
  delfunction Range

Execute(ale#lsp#response#ReadDiagnostics() should handle errors):
  AssertEqual ['filename.ts', [
  \   {
  \     'type': 'E',
  \     'message': 'Something went wrong!',
  \     'lnum': 3,
  \     'col': 11,
  \     'end_lnum': 5,
  \     'end_col': 16,
  \     'nr': 'some-error',
  \   }
  \ ]],
  \ ale#lsp#response#ReadDiagnostics({'uri': 'filename.ts', 'diagnostics': [
  \   {
  \     'severity': 1,
  \     'range': Range(2, 10, 4, 15),
  \     'code': 'some-error',
  \     'message': 'Something went wrong!',
  \   },
  \ ]})

Execute(ale#lsp#response#ReadDiagnostics() should handle warnings):
  AssertEqual ['filename.ts', [
  \   {
  \     'type': 'W',
  \     'message': 'Something went wrong!',
  \     'lnum': 2,
  \     'col': 4,
  \     'end_lnum': 2,
  \     'end_col': 4,
  \     'nr': 'some-warning',
  \   }
  \ ]],
  \ ale#lsp#response#ReadDiagnostics({'uri': 'filename.ts', 'diagnostics': [
  \   {
  \     'severity': 2,
  \     'range': Range(1, 3, 1, 3),
  \     'code': 'some-warning',
  \     'message': 'Something went wrong!',
  \   },
  \ ]})

Execute(ale#lsp#response#ReadDiagnostics() should treat messages with missing severity as errors):
  AssertEqual ['filename.ts', [
  \   {
  \     'type': 'E',
  \     'message': 'Something went wrong!',
  \     'lnum': 3,
  \     'col': 11,
  \     'end_lnum': 5,
  \     'end_col': 16,
  \     'nr': 'some-error',
  \   }
  \ ]],
  \ ale#lsp#response#ReadDiagnostics({'uri': 'filename.ts', 'diagnostics': [
  \   {
  \     'range': Range(2, 10, 4, 15),
  \     'code': 'some-error',
  \     'message': 'Something went wrong!',
  \   },
  \ ]})

Execute(ale#lsp#response#ReadDiagnostics() should handle messages without codes):
  AssertEqual ['filename.ts', [
  \   {
  \     'type': 'E',
  \     'message': 'Something went wrong!',
  \     'lnum': 3,
  \     'col': 11,
  \     'end_lnum': 5,
  \     'end_col': 16,
  \   }
  \ ]],
  \ ale#lsp#response#ReadDiagnostics({'uri': 'filename.ts', 'diagnostics': [
  \   {
  \     'range': Range(2, 10, 4, 15),
  \     'message': 'Something went wrong!',
  \   },
  \ ]})

Execute(ale#lsp#response#ReadDiagnostics() should handle multiple messages):
  AssertEqual ['filename.ts', [
  \   {
  \     'type': 'E',
  \     'message': 'Something went wrong!',
  \     'lnum': 1,
  \     'col': 3,
  \     'end_lnum': 1,
  \     'end_col': 3,
  \   },
  \   {
  \     'type': 'W',
  \     'message': 'A warning',
  \     'lnum': 2,
  \     'col': 5,
  \     'end_lnum': 2,
  \     'end_col': 5,
  \   },
  \ ]],
  \ ale#lsp#response#ReadDiagnostics({'uri': 'filename.ts', 'diagnostics': [
  \   {
  \     'range': Range(0, 2, 0, 2),
  \     'message': 'Something went wrong!',
  \   },
  \   {
  \     'severity': 2,
  \     'range': Range(1, 4, 1, 4),
  \     'message': 'A warning',
  \   },
  \ ]})