From d25daddcba32b754e0072481b5da258e7f5562b6 Mon Sep 17 00:00:00 2001
From: webwarrior <reg@webwarrior.ws>
Date: Tue, 9 Jan 2024 10:32:02 +0100
Subject: [PATCH] DisallowShadowing: docs and config

Added config and docs for DisallowShadowing rule.
---
 docs/content/how-tos/rule-configuration.md    |  1 +
 docs/content/how-tos/rules/FL0084.md          | 29 +++++++++++++++++++
 .../Application/Configuration.fs              |  9 ++++--
 src/FSharpLint.Core/fsharplint.json           |  1 +
 4 files changed, 38 insertions(+), 2 deletions(-)
 create mode 100644 docs/content/how-tos/rules/FL0084.md

diff --git a/docs/content/how-tos/rule-configuration.md b/docs/content/how-tos/rule-configuration.md
index 41c276352..2405a2acf 100644
--- a/docs/content/how-tos/rule-configuration.md
+++ b/docs/content/how-tos/rule-configuration.md
@@ -124,3 +124,4 @@ The following rules can be specified for linting.
 - [NestedFunctionNames (FL0081)](rules/FL0081.html)
 - [UsedUnderscorePrefixedElements (FL0082)](rules/FL0082.html)
 - [UnneededRecKeyword (FL0083)](rules/FL0083.html)
+- [DisallowShadowing (FL0084)](rules/FL0084.html)
diff --git a/docs/content/how-tos/rules/FL0084.md b/docs/content/how-tos/rules/FL0084.md
new file mode 100644
index 000000000..19258a26e
--- /dev/null
+++ b/docs/content/how-tos/rules/FL0084.md
@@ -0,0 +1,29 @@
+---
+title: FL0084
+category: how-to
+hide_menu: true
+---
+
+# DisallowShadowing (FL0084)
+
+*Introduced in `0.23.8`*
+
+## Cause
+
+A variable or parameter shadows another one with the same name.
+
+## Rationale
+
+Sometimes shadowing can cause confusion.
+
+## How To Fix
+
+Rename varaible or parameter in question so it has unique name in its scope.
+
+## Rule Settings
+
+    {
+        "disallowShadowing": {
+            "enabled": true
+        }
+    }
diff --git a/src/FSharpLint.Core/Application/Configuration.fs b/src/FSharpLint.Core/Application/Configuration.fs
index 20c30cc4c..534da1c2d 100644
--- a/src/FSharpLint.Core/Application/Configuration.fs
+++ b/src/FSharpLint.Core/Application/Configuration.fs
@@ -324,7 +324,8 @@ type ConventionsConfig =
       favourReRaise:EnabledConfig option
       favourConsistentThis:RuleConfig<FavourConsistentThis.Config> option
       suggestUseAutoProperty:EnabledConfig option
-      usedUnderscorePrefixedElements:EnabledConfig option }
+      usedUnderscorePrefixedElements:EnabledConfig option
+      disallowShadowing:EnabledConfig option }
 with
     member this.Flatten() =
         [|
@@ -348,6 +349,7 @@ with
             this.numberOfItems |> Option.map (fun config -> config.Flatten()) |> Option.toArray |> Array.concat
             this.binding |> Option.map (fun config -> config.Flatten()) |> Option.toArray |> Array.concat
             this.suggestUseAutoProperty |> Option.bind (constructRuleIfEnabled SuggestUseAutoProperty.rule) |> Option.toArray
+            this.disallowShadowing |> Option.bind (constructRuleIfEnabled DisallowShadowing.rule) |> Option.toArray
         |] |> Array.concat
 
 type TypographyConfig =
@@ -469,7 +471,8 @@ type Configuration =
       TrailingNewLineInFile:EnabledConfig option
       NoTabCharacters:EnabledConfig option
       NoPartialFunctions:RuleConfig<NoPartialFunctions.Config> option
-      SuggestUseAutoProperty:EnabledConfig option }
+      SuggestUseAutoProperty:EnabledConfig option
+      DisallowShadowing:EnabledConfig option }
 with
     static member Zero = {
         Global = None
@@ -559,6 +562,7 @@ with
         NoTabCharacters = None
         NoPartialFunctions = None
         SuggestUseAutoProperty = None
+        DisallowShadowing = None
     }
 
 // fsharplint:enable RecordFieldNames
@@ -711,6 +715,7 @@ let flattenConfig (config:Configuration) =
             config.TrailingNewLineInFile |> Option.bind (constructRuleIfEnabled TrailingNewLineInFile.rule)
             config.NoTabCharacters |> Option.bind (constructRuleIfEnabled NoTabCharacters.rule)
             config.NoPartialFunctions |> Option.bind (constructRuleWithConfig NoPartialFunctions.rule)
+            config.DisallowShadowing |> Option.bind (constructRuleIfEnabled DisallowShadowing.rule)
         |] |> Array.choose id
 
     if config.NonPublicValuesNames.IsSome &&
diff --git a/src/FSharpLint.Core/fsharplint.json b/src/FSharpLint.Core/fsharplint.json
index 70156d75e..cb3574c7f 100644
--- a/src/FSharpLint.Core/fsharplint.json
+++ b/src/FSharpLint.Core/fsharplint.json
@@ -290,6 +290,7 @@
         }
     },
     "suggestUseAutoProperty": { "enabled": false },
+    "disallowShadowing": { "enabled": false },
     "avoidTooShortNames": { "enabled": false },
     "asyncExceptionWithoutReturn": { "enabled": false },
     "unneededRecKeyword": { "enabled": true },