Add exhaustive test suite for 'cabal path' cmd

We test that each query honours cabal.project files, cli parameters, and
is composable with the other query flags.

We extend the test output normalisers for ghc compiler location and
cabal-install version, as the 'cabal path' command outputs the exact ghc
and ghc-pkg location. In addition, the json output format is versioned
on the cabal-install version.

Currently, we query the cabal-install version on each test normalisation
run. This might be unnecessary expensive, and could be avoided by
introducing a 'cabalProgram' that specifies how the program version can
be found. This way, we can cache the version query.

cabal-testsuite/PackageTests/Path/All/cabal.test.hs

@@ -1,3 +1,27 @@
 import Test.Cabal.Prelude
+import Data.List (subsequences)
+
+allOutputFormats =
+  [ "json"
+  , "key-value"
+  ]
+
+allFlags =
+  [ "--compiler-info"
+  , "--cache-dir"
+  , "--logs-dir"
+  , "--store-dir"
+  , "--config-file"
+  , "--installdir"
+  ]
+
+main = cabalTest $ do
+  forM_ allOutputFormats $ \outputFormat -> do
+    -- Order of flags should not matter, neither does any flag depend on the
+    -- existence of any other flag.
+    --
+    -- 'subsequences' generated "n over k" for k in (1 .. n)
+    forM_ (subsequences allFlags) $ \flags -> do
+      cabal "path" $ ["--output-format", outputFormat] <> flags
+
 
-main = cabalTest . void $ cabal "path" ["-z", "--output-format=key-value"]

cabal-testsuite/PackageTests/Path/Compiler/cabal.out

@@ -0,0 +1,6 @@
+# cabal path
+compiler-flavour: ghc
+compiler-id: ghc-<GHCVER>
+compiler-path: <GHCPATH>
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","compiler":{"flavour":"ghc","id":"ghc-<GHCVER>","path":"<GHCPATH>"}}

cabal-testsuite/PackageTests/Path/Compiler/cabal.test.hs

@@ -0,0 +1,6 @@
+import Test.Cabal.Prelude
+
+main = cabalTest $ do
+  -- Basic output
+  void $ cabal "path" ["-z", "--output-format=key-value", "--compiler-info"]
+  void $ cabal "path" ["-z", "--output-format=json", "--compiler-info"]

cabal-testsuite/PackageTests/Path/Config/cabal.out

@@ -0,0 +1,64 @@
+# cabal path
+<ROOT>/cabal.dist/home/.cabal/packages
+# cabal path
+<ROOT>/cabal.dist/home/.cabal/logs
+# cabal path
+<ROOT>/cabal.dist/home/.cabal/store
+# cabal path
+<ROOT>/cabal.dist/home/.cabal/config
+# cabal path
+<ROOT>/cabal.dist/home/.cabal/bin
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","cache-dir":"<ROOT>/cabal.dist/home/.cabal/packages"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","logs-dir":"<ROOT>/cabal.dist/home/.cabal/logs"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","store-dir":"<ROOT>/cabal.dist/home/.cabal/store"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","config-file":"<ROOT>/cabal.dist/home/.cabal/config"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","installdir":"<ROOT>/cabal.dist/home/.cabal/bin"}
+# cabal path
+test-dir
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","store-dir":"test-dir"}
+# cabal path
+my-cache-dir
+# cabal path
+my-logs-dir
+# cabal path
+my-store-dir
+# cabal path
+fake-cabal.config
+# cabal path
+my-installdir
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","cache-dir":"my-cache-dir"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","logs-dir":"my-logs-dir"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","store-dir":"my-store-dir"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","config-file":"fake-cabal.config"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","installdir":"my-installdir"}
+# cabal path
+my-cache-dir
+# cabal path
+my-logs-dir
+# cabal path
+my-store-dir
+# cabal path
+<ROOT>/cabal.dist/home/.cabal/config
+# cabal path
+my-installdir
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","cache-dir":"my-cache-dir"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","logs-dir":"my-logs-dir"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","store-dir":"my-store-dir"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","config-file":"<ROOT>/cabal.dist/home/.cabal/config"}
+# cabal path
+{"cabal-install-version":"<CABAL_INSTALL_VER>","installdir":"my-installdir"}

cabal-testsuite/PackageTests/Path/Config/cabal.test.hs

@@ -0,0 +1,43 @@
+import Test.Cabal.Prelude
+
+main = cabalTest $ do
+  -- Basic output
+  void $ cabal "path" ["-z", "--output-format=key-value", "--cache-dir"]
+  void $ cabal "path" ["-z", "--output-format=key-value", "--logs-dir"]
+  void $ cabal "path" ["-z", "--output-format=key-value", "--store-dir"]
+  void $ cabal "path" ["-z", "--output-format=key-value", "--config-file"]
+  void $ cabal "path" ["-z", "--output-format=key-value", "--installdir"]
+  -- Works for json, too
+  void $ cabal "path" ["-z", "--output-format=json", "--cache-dir"]
+  void $ cabal "path" ["-z", "--output-format=json", "--logs-dir"]
+  void $ cabal "path" ["-z", "--output-format=json", "--store-dir"]
+  void $ cabal "path" ["-z", "--output-format=json", "--config-file"]
+  void $ cabal "path" ["-z", "--output-format=json", "--installdir"]
+  -- Honours cli overwrites
+  void $ cabalG ["--store-dir=test-dir"] "path" ["-z", "--output-format=key-value", "--store-dir"]
+  void $ cabalG ["--store-dir=test-dir"] "path" ["-z", "--output-format=json", "--store-dir"]
+  -- Honour config file overwrites:
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=key-value", "--cache-dir"]
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=key-value", "--logs-dir"]
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=key-value", "--store-dir"]
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=key-value", "--config-file"]
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=key-value", "--installdir"]
+
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=json", "--cache-dir"]
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=json", "--logs-dir"]
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=json", "--store-dir"]
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=json", "--config-file"]
+  void $ cabalG ["--config-file=fake-cabal.config"] "path" ["-z", "--output-format=json", "--installdir"]
+
+  -- Honour cabal.project file
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=key-value", "--cache-dir"]
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=key-value", "--logs-dir"]
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=key-value", "--store-dir"]
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=key-value", "--config-file"]
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=key-value", "--installdir"]
+  -- Works for json, too
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=json", "--cache-dir"]
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=json", "--logs-dir"]
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=json", "--store-dir"]
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=json", "--config-file"]
+  void $ cabal "path" ["--project-file=fake.cabal.project", "--output-format=json", "--installdir"]

cabal-testsuite/PackageTests/Path/Config/config.cabal

@@ -0,0 +1,5 @@
+cabal-version: 3.0
+name: config
+version: 0.1
+
+library

cabal-testsuite/PackageTests/Path/Config/fake-cabal.config

@@ -0,0 +1,11 @@
+-- this is a test file, dont use it
+repository hackage.haskell.org
+  url: http://hackage.haskell.org/
+  -- secure: True
+  -- root-keys:
+  -- key-threshold: 3
+
+logs-dir: my-logs-dir
+store-dir: my-store-dir
+remote-repo-cache: my-cache-dir
+installdir: my-installdir

cabal-testsuite/PackageTests/Path/Config/fake.cabal.project

@@ -0,0 +1,6 @@
+packages: ./
+
+logs-dir: my-logs-dir
+store-dir: my-store-dir
+remote-repo-cache: my-cache-dir
+installdir: my-installdir

cabal-testsuite/src/Test/Cabal/Monad.hs

@@ -300,9 +300,7 @@ runTestM mode m =
                 program_db1
                 verbosity
 
-    ghcLocation <- case lookupProgramByName "ghc" program_db2 of
-        Nothing -> fail "runTestM.lookupProgramByName: No location for 'ghc' was found"
-        Just ghcProg -> pure $ programPath ghcProg
+    (configuredGhcProg, _) <- requireProgram verbosity ghcProgram program_db2
 
     program_db3 <-
         reconfigurePrograms verbosity
@@ -325,7 +323,7 @@ runTestM mode m =
                     testProgramDb = program_db,
                     testPlatform = platform,
                     testCompiler = comp,
-                    testCompilerPath =  ghcLocation,
+                    testCompilerPath = programPath configuredGhcProg,
                     testPackageDBStack = db_stack,
                     testVerbosity = verbosity,
                     testMtimeChangeDelay = Nothing,
@@ -530,6 +528,16 @@ mkNormalizerEnv = do
 
     canonicalizedTestTmpDir <- liftIO $ canonicalizePath (testTmpDir env)
 
+    -- 'cabal' is configured in the package-db, but doesn't specify how to find the program version
+    -- Thus we find the program location, if it exists, and query for the program version for
+    -- output normalisation.
+    cabalVersionM <- do
+        cabalProgM <- needProgramM "cabal"
+        case cabalProgM of
+            Nothing -> pure Nothing
+            Just cabalProg -> do
+                liftIO (findProgramVersion "--numeric-version" id (testVerbosity env) (programPath cabalProg))
+
     return NormalizerEnv {
         normalizerRoot
             = addTrailingPathSeparator (testSourceDir env),
@@ -548,7 +556,9 @@ mkNormalizerEnv = do
         normalizerPlatform
             = testPlatform env,
         normalizerCabalVersion
-            = cabalVersionLibrary
+            = cabalVersionLibrary,
+        normalizerCabalInstallVersion
+            = cabalVersionM
     }
 
 cabalVersionLibrary :: Version
@@ -561,6 +571,11 @@ requireProgramM program = do
         requireProgram (testVerbosity env) program (testProgramDb env)
     return configured_program
 
+needProgramM :: String -> TestM (Maybe ConfiguredProgram)
+needProgramM program = do
+    env <- getTestEnv
+    return $ lookupProgramByName program (testProgramDb env)
+
 programPathM :: Program -> TestM FilePath
 programPathM program = do
     fmap programPath (requireProgramM program)

cabal-testsuite/src/Test/Cabal/OutputNormalizer.hs

@@ -63,20 +63,22 @@ normalizeOutput nenv =
                    "<GHCVER>"
         else id)
   . normalizeBuildInfoJson
-  . normalizePathCmdOutput
+  . maybe id normalizePathCmdOutput (normalizerCabalInstallVersion nenv)
   -- hackage-security locks occur non-deterministically
   . resub "(Released|Acquired|Waiting) .*hackage-security-lock\n" ""
   where
     packageIdRegex pid =
         resub (posixRegexEscape (display pid) ++ "(-[A-Za-z0-9.-]+)?")
               (prettyShow (packageName pid) ++ "-<VERSION>")
 
-    normalizePathCmdOutput =
+    normalizePathCmdOutput cabalInstallVersion =
       -- clear the ghc path out of all supported output formats
       resub ("compiler-path: " <> posixRegexEscape (normalizerGhcPath nenv))
           "compiler-path: <GHCPATH>"
       . resub ("\"compiler-path\"\\s*:\\s*\"" <> posixRegexEscape (normalizerGhcPath nenv) <> "\"")
           "\"compiler-path\": \"<GHCPATH>\""
+      . resub (display cabalInstallVersion)
+          "<CABAL_INSTALL_VER>"
 
     -- 'build-info.json' contains a plethora of host system specific information.
     --
@@ -116,6 +118,7 @@ data NormalizerEnv = NormalizerEnv
     , normalizerKnownPackages :: [PackageId]
     , normalizerPlatform      :: Platform
     , normalizerCabalVersion  :: Version
+    , normalizerCabalInstallVersion :: Maybe Version
     }
 
 posixSpecialChars :: [Char]