Make FileSystemWatcher more reliable

src/SqlClient.Samples/WebApi.Controllers/DataAccess.fs

@@ -5,7 +5,7 @@ open FSharp.Data
 [<Literal>]
 let AdventureWorks2012 = "name=AdventureWorks2012"
 
-type QueryProducts = SqlCommandProvider<"T-SQL\Products.sql", AdventureWorks2012, DataDirectory = "App_Data">
+type QueryProducts = SqlCommandProvider<"T-SQL/Products.sql", AdventureWorks2012, DataDirectory = "App_Data">
 
 type AdventureWorks = SqlProgrammabilityProvider<AdventureWorks2012, DataDirectory = "App_Data">
 

src/SqlClient.Tests/ConfigurationTest.fs

@@ -26,6 +26,15 @@ let RuntimeConfig () =
     Configuration.GetConnectionStringAtRunTime name
     |> should equal ConfigurationManager.ConnectionStrings.[name].ConnectionString
 
+[<Fact>]
+let CheckValidFileName() = 
+    let expected = Some "c:\\mysqlfiles\\test.sql"
+    Configuration.GetValidFileName("test.sql", "c:\\mysqlfiles") |> should equal expected
+    Configuration.GetValidFileName("../test.sql", "c:\\mysqlfiles\\subfolder") |> should equal expected
+    Configuration.GetValidFileName("c:\\mysqlfiles/test.sql", "d:\\otherdrive") |> should equal expected
+    Configuration.GetValidFileName("../mysqlfiles/test.sql", "c:\\otherfolder") |> should equal expected
+    Configuration.GetValidFileName("a/b/c/../../../test.sql", "c:\\mysqlfiles") |> should equal expected
+
 type Get42RelativePath = SqlCommandProvider<"sampleCommand.sql", "name=AdventureWorks2012", ResolutionFolder="MySqlFolder">
 
 type Get42 = SqlCommandProvider<"SELECT 42", "name=AdventureWorks2012", ConfigFile = "appWithInclude.config">

src/SqlClient/Configuration.fs

@@ -20,27 +20,34 @@ open System.Threading.Tasks
 open System.Collections.Generic
 
 type Configuration() =    
-    static let isInvalidPathChars = HashSet(Path.GetInvalidPathChars())
+    static let invalidPathChars = HashSet(Path.GetInvalidPathChars())
+    static let invalidFileChars = HashSet(Path.GetInvalidFileNameChars())
+
+    static member GetValidFileName (file:string, resolutionFolder:string) = 
+        if (file.Contains "\n") || (resolutionFolder.Contains "\n") then None else
+        let f = Path.Combine(resolutionFolder, file)
+        if invalidPathChars.Overlaps (Path.GetDirectoryName f) ||
+           invalidFileChars.Overlaps (Path.GetFileName f) then None 
+        else 
+           // Canonicalizing the path may throw on bad input, the check above does not cover every error.
+           try Some (Path.GetFullPath f) with | _ -> None
 
     static member ParseTextAtDesignTime(commandTextOrPath : string, resolutionFolder, invalidateCallback) =
-        if isInvalidPathChars.Overlaps( commandTextOrPath)         
-        then commandTextOrPath, None
-        else
-            let path = Path.Combine(resolutionFolder, commandTextOrPath)
-            if File.Exists(path) |> not 
-            then commandTextOrPath, None
-            else
-                if  Path.GetExtension(commandTextOrPath) <> ".sql" then failwith "Only files with .sql extension are supported"
-                let watcher = new FileSystemWatcher(Filter = commandTextOrPath, Path = resolutionFolder)
+        match Configuration.GetValidFileName (commandTextOrPath, resolutionFolder) with
+        | Some path when File.Exists path ->
+                if Path.GetExtension(path) <> ".sql" then failwith "Only files with .sql extension are supported"
+                let watcher = new FileSystemWatcher(Filter = Path.GetFileName path, Path = Path.GetDirectoryName path)
                 watcher.Changed.Add(fun _ -> invalidateCallback())
                 watcher.Renamed.Add(fun _ -> invalidateCallback())
+                watcher.Deleted.Add(fun _ -> invalidateCallback())
                 watcher.EnableRaisingEvents <- true   
                 let task = Task.Factory.StartNew(fun () -> 
                         use stream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
                         use reader = new StreamReader(stream)
                         reader.ReadToEnd())
                 if not (task.Wait(TimeSpan.FromSeconds(1.))) then failwithf "Couldn't read command from file %s" path
                 task.Result, Some watcher 
+        | _ -> commandTextOrPath, None
 
     static member ParseConnectionStringName(s: string) =
         match s.Trim().Split([|'='|], 2, StringSplitOptions.RemoveEmptyEntries) with