Before: " Load the file which defines the linter. runtime ale_linters/terraform/terraform.vim call ale#test#SetDirectory('/testplugin/test/terraform_files') call ale#test#SetFilename('providers.tf') After: " Unload all linters again. call ale#linter#Reset() call ale#test#RestoreDirectory() Execute(The output should be correct): AssertEqual \ [ \ { \ 'lnum': 17, \ 'col': 13, \ 'filename': ale#path#Simplify(g:dir . '/providers.tf'), \ 'type': 'W', \ 'text': 'Terraform 0.13 and earlier allowed provider version', \ }, \ { \ 'lnum': 0, \ 'col': 0, \ 'filename': ale#path#Simplify(g:dir . '/providers.tf'), \ 'type': 'E', \ 'text': 'Plugin reinitialization required. Please run "terraform"', \ } \ ], \ ale_linters#terraform#terraform#Handle(bufnr(''), [ \ '{', \ '"valid": false,', \ '"error_count": 1,', \ '"warning_count": 1,', \ '"diagnostics": [', \ ' {', \ ' "severity": "warning",', \ ' "summary": "Version constraints inside provider configuration blocks are deprecated",', \ ' "detail": "Terraform 0.13 and earlier allowed provider version",', \ ' "range": {', \ ' "filename": "providers.tf",', \ ' "start": {', \ ' "line": 17,', \ ' "column": 13,', \ ' "byte": 669', \ ' },', \ ' "end": {', \ ' "line": 17,', \ ' "column": 24,', \ ' "byte": 680', \ ' }', \ ' }', \ ' },', \ ' {', \ ' "severity": "error",', \ ' "summary": "Could not load plugin",', \ ' "detail": "Plugin reinitialization required. Please run \"terraform\""', \ ' }', \ ' ]', \ '}', \ ])