Parse .cabal files; show error and warning diagnostics (#2954)

* Extract cabal plugin in its own package

* hls-cabal-plugin: Add plugin

Add golden parse test for test/testdata/simple.cabal
Add module Ide.Plugin.Cabal.Diag
Also: add -Wall

Add parseCabalFileContents
Use VFS for cabal file contents

Diagnostics
 * Parse and display Errors
 * Parse and display Warnings

Code Actions
 * Code Action for License Field

* Add CI workflow

* Add test-suite for hls-cabal-plugin

* Fix various cabal issues

* Update Codeowners file for hls-cabal-plugin

* Document Bytestring is UTF-8 encoded

Co-authored-by: Julian Ospald <[email protected]>

* Remove code duplication

* Add cabal files of interest and kick function

Configure a "kick" function for cabal files that is run when the shake
queue needs to be restarted.
Copy pastes from ghcide and 'files of interest'. Maybe more abstraction
needed.

* Add more documentation

* Mark flaky test-case as flaky with issue ref

* Make fendor the only CODEOWNER for hls-cabal-plugin

* Add missing extra-source-files for hls-cabal-plugin

* Add proper CHANGELOG entry for the first version of hls-cabal-plugin

* Add support for Cabal 3.8

* Set diagnostics source to cabal

* Remove unused function

* Add unit tests for code action utilities

* Remove overly specific logging of diagnostics from hls-cabal-plugin

* Improve logging for Cabal FOIs

* Add Range manipulation functions

* Use Range manipulation functions from hls-plugin-api

* Add more documentation for crucial shake restart function

* Add hls-cabal-plugin features to features.md

* Re-use existing GetFileContents rule

Co-authored-by: Fendor <[email protected]>
Co-authored-by: fendor <[email protected]>
Co-authored-by: Julian Ospald <[email protected]>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Author: 4 people

Diff for: .github/workflows/hackage.yml

@@ -28,6 +28,7 @@ jobs:
       matrix:
         package: ["hie-compat", "hls-graph", "shake-bench",
                   "hls-plugin-api", "ghcide", "hls-test-utils",
+                  "hls-cabal-plugin",
                   "hls-brittany-plugin", "hls-floskell-plugin", "hls-fourmolu-plugin",
                   "hls-ormolu-plugin", "hls-stylish-haskell-plugin",
                   "hls-class-plugin", "hls-eval-plugin", "hls-explicit-imports-plugin",

Diff for: .github/workflows/test.yml

@@ -259,6 +259,10 @@ jobs:
         name: Test hls-cabal-fmt-plugin test suite
         run: cabal test hls-cabal-fmt-plugin --flag=isolateTests --test-options="$TEST_OPTS" || cabal test hls-cabal-fmt-plugin --flag=isolateTests --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-cabal-fmt-plugin --flag=isolateTests --test-options="$TEST_OPTS"
 
+      - if: matrix.test
+        name: Test hls-cabal-plugin test suite
+        run: cabal test hls-cabal-plugin --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-cabal-plugin --test-options="$TEST_OPTS"
+
   test_post_job:
     if: always()
     runs-on: ubuntu-latest

Diff for: CODEOWNERS

@@ -9,6 +9,7 @@
 # Plugins
 /plugins/hls-alternate-number-format-plugin @drsooch
 /plugins/hls-brittany-plugin @fendor
+/plugins/hls-cabal-plugin @fendor
 /plugins/hls-cabal-fmt-plugin @VeryMilkyJoe @fendor
 /plugins/hls-call-hierarchy-plugin @July541
 /plugins/hls-class-plugin @Ailrun

Diff for: cabal.project

@@ -8,6 +8,7 @@ packages:
          ./ghcide/test
          ./hls-plugin-api
          ./hls-test-utils
+         ./plugins/hls-cabal-plugin
          ./plugins/hls-cabal-fmt-plugin
          ./plugins/hls-tactics-plugin
          ./plugins/hls-brittany-plugin

Diff for: docs/features.md

@@ -44,6 +44,12 @@ Provided by: `hls-stan-plugin`
 
 Provides Stan hints as diagnostics.
 
+### Cabal parse errors and warnings
+
+Provided by: `hls-cabal-plugin`
+
+Provides errors and warnings from Cabal as diagnostics
+
 ## Hovers
 
 Provided by: `ghcide`
@@ -308,6 +314,14 @@ Expand record wildcards, explicitly listing all record fields as field puns.
 
 ![Explicit Wildcard Demo](../plugins/hls-explicit-record-fields-plugin/wildcard.gif)
 
+### Unknown SPDX License suggestion
+
+Provided by: `hls-cabal-plugin`
+
+Code action kind: `quickfix`
+
+Correct common misspelling of SPDX Licenses such as `BSD-3-Clause`.
+
 ## Code lenses
 
 ### Add type signature

Diff for: haskell-language-server.cabal

@@ -63,6 +63,12 @@ flag ignore-plugins-ghc-bounds
   default:     False
   manual:      True
 
+
+flag cabal
+  description: Enable cabal plugin
+  default:     True
+  manual:      True
+
 flag class
   description: Enable class plugin
   default:     True
@@ -215,6 +221,11 @@ common cabalfmt
     build-depends: hls-cabal-fmt-plugin ^>= 0.1.0.0
     cpp-options: -Dhls_cabalfmt
 
+common cabal
+  if flag(cabal)
+    build-depends: hls-cabal-plugin ^>= 0.1
+    cpp-options: -Dhls_cabal
+
 common class
   if flag(class)
     build-depends: hls-class-plugin ^>= 1.1
@@ -358,6 +369,7 @@ library
                   , warnings
                   , pedantic
                   -- plugins
+                  , cabal
                   , callHierarchy
                   , cabalfmt
                   , changeTypeSignature

Diff for: hls-plugin-api/src/Ide/PluginUtils.hs

@@ -2,9 +2,12 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TypeFamilies      #-}
 module Ide.PluginUtils
-  ( WithDeletions(..),
-    getProcessID,
+  ( -- * LSP Range manipulation functions
     normalize,
+    extendNextLine,
+    extendLineStart,
+    WithDeletions(..),
+    getProcessID,
     makeDiffTextEdit,
     makeDiffTextEditAdditive,
     diffText,
@@ -67,9 +70,27 @@ import qualified Text.Megaparsec.Char.Lexer      as P
 -- ---------------------------------------------------------------------
 
 -- | Extend to the line below and above to replace newline character.
+--
+-- >>> normalize (Range (Position 5 5) (Position 5 10))
+-- Range (Position 5 0) (Position 6 0)
 normalize :: Range -> Range
-normalize (Range (Position sl _) (Position el _)) =
-  Range (Position sl 0) (Position (el + 1) 0)
+normalize = extendLineStart . extendNextLine
+
+-- | Extend 'Range' to the start of the next line.
+--
+-- >>> extendNextLine (Range (Position 5 5) (Position 5 10))
+-- Range (Position 5 5) (Position 6 0)
+extendNextLine :: Range -> Range
+extendNextLine (Range s (Position el _)) =
+  Range s (Position (el + 1) 0)
+
+-- | Extend 'Range' to the start of the current line.
+--
+-- >>> extendLineStart (Range (Position 5 5) (Position 5 10))
+-- Range (Position 5 0) (Position 5 10)
+extendLineStart :: Range -> Range
+extendLineStart (Range (Position sl _) e) =
+  Range (Position sl 0) e
 
 -- ---------------------------------------------------------------------
 

Diff for: hls-test-utils/src/Test/Hls.hs

@@ -16,6 +16,7 @@ module Test.Hls
     defaultTestRunner,
     goldenGitDiff,
     goldenWithHaskellDoc,
+    goldenWithCabalDoc,
     goldenWithHaskellDocFormatter,
     goldenWithCabalDocFormatter,
     def,
@@ -124,12 +125,35 @@ goldenWithHaskellDoc
   -> FilePath
   -> (TextDocumentIdentifier -> Session ())
   -> TestTree
-goldenWithHaskellDoc plugin title testDataDir path desc ext act =
+goldenWithHaskellDoc = goldenWithDoc "haskell"
+
+goldenWithCabalDoc
+  :: PluginDescriptor IdeState
+  -> TestName
+  -> FilePath
+  -> FilePath
+  -> FilePath
+  -> FilePath
+  -> (TextDocumentIdentifier -> Session ())
+  -> TestTree
+goldenWithCabalDoc = goldenWithDoc "cabal"
+
+goldenWithDoc
+  :: T.Text
+  -> PluginDescriptor IdeState
+  -> TestName
+  -> FilePath
+  -> FilePath
+  -> FilePath
+  -> FilePath
+  -> (TextDocumentIdentifier -> Session ())
+  -> TestTree
+goldenWithDoc fileType plugin title testDataDir path desc ext act =
   goldenGitDiff title (testDataDir </> path <.> desc <.> ext)
   $ runSessionWithServer plugin testDataDir
   $ TL.encodeUtf8 . TL.fromStrict
   <$> do
-    doc <- openDoc (path <.> ext) "haskell"
+    doc <- openDoc (path <.> ext) fileType
     void waitForBuildQueue
     act doc
     documentContents doc

Diff for: plugins/hls-cabal-plugin/CHANGELOG.md

@@ -0,0 +1,6 @@
+# Revision history for hls-cabal-plugin
+
+## 0.1.0.0 -- YYYY-mm-dd
+
+* Provide Diagnostics on parse errors and warnings for .cabal files
+* Provide CodeAction for the common SPDX License mistake "BSD3" instead of "BSD-3-Clause"

Diff for: plugins/hls-cabal-plugin/LICENSE

@@ -0,0 +1,20 @@
+Copyright (c) 2022 Fendor
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Diff for: plugins/hls-cabal-plugin/hls-cabal-plugin.cabal

@@ -0,0 +1,81 @@
+cabal-version:      3.0
+name:               hls-cabal-plugin
+version:            0.1.0.0
+synopsis:           Cabal integration plugin with Haskell Language Server
+description:
+  Please see the README on GitHub at <https://github.com/haskell/haskell-language-server#readme>
+
+homepage:
+license:            MIT
+license-file:       LICENSE
+author:             Fendor
+maintainer:         [email protected]
+category:           Development
+extra-source-files:
+  CHANGELOG.md
+  test/testdata/*.cabal
+  test/testdata/simple-cabal/A.hs
+  test/testdata/simple-cabal/cabal.project
+  test/testdata/simple-cabal/hie.yaml
+  test/testdata/simple-cabal/simple-cabal.cabal
+
+common warnings
+  ghc-options: -Wall
+
+library
+  import:           warnings
+  exposed-modules:
+    Ide.Plugin.Cabal
+    Ide.Plugin.Cabal.Diagnostics
+    Ide.Plugin.Cabal.LicenseSuggest
+    Ide.Plugin.Cabal.Parse
+
+  build-depends:
+    , base                  >=4.12     && <5
+    , bytestring
+    -- Ideally, we only want to support a single Cabal version, supporting
+    -- older versions is completely pointless since Cabal is backwards compatible,
+    -- the latest Cabal version can parse all versions of the Cabal file format.
+    --
+    -- However, stack is making this difficult, if we change the version of Cabal,
+    -- we essentially need to make sure all other packages in the snapshot have their
+    -- Cabal dependency version relaxed.
+    -- Most packages have a Hackage revision, but stack won't pick these up (for sensible reasons)
+    -- automatically, forcing us to manually update the packages revision id.
+    -- This is a lot of work for almost zero benefit, so we just allow more versions here
+    -- and we eventually completely drop support for building HLS with stack.
+    , Cabal                 ^>=3.2 || ^>=3.4 || ^>=3.6 || ^>= 3.8
+    , deepseq
+    , directory
+    , extra                 >=1.7.4
+    , ghcide                ^>= 1.8
+    , hashable
+    , hls-plugin-api        ^>=1.5
+    , hls-graph             ^>=1.8
+    , lsp                   ^>=1.6.0.0
+    , lsp-types             ^>=1.6.0.0
+    , regex-tdfa            ^>=1.3.1
+    , stm
+    , text
+    , unordered-containers  >=0.2.10.0
+
+  hs-source-dirs:   src
+  default-language: Haskell2010
+
+test-suite tests
+  import:           warnings
+  default-language: Haskell2010
+  type:             exitcode-stdio-1.0
+  hs-source-dirs:   test
+  main-is:          Main.hs
+  build-depends:
+    , base
+    , bytestring
+    , filepath
+    , ghcide
+    , hls-cabal-plugin
+    , hls-test-utils    ^>=1.4
+    , lens
+    , lsp-types
+    , tasty-hunit
+    , text