Merge pull request #837 from bergmeister/FixPSUseDeclaredVarsMoreThanAssignments_StrongTyping_Issue832

Fix FixPSUseDeclaredVarsMoreThanAssignments to also detect variables that are strongly typed

Author: JamesWTruher

Rules/UseDeclaredVarsMoreThanAssignments.cs

@@ -135,6 +135,17 @@ private IEnumerable<DiagnosticRecord> AnalyzeScriptBlockAst(ScriptBlockAst scrip
                 // Only checks for the case where lhs is a variable. Ignore things like $foo.property
                 VariableExpressionAst assignmentVarAst = assignmentAst.Left as VariableExpressionAst;
 
+                if (assignmentVarAst == null)
+                {
+                    // If the variable is declared in a strongly typed way, e.g. [string]$s = 'foo' then the type is ConvertExpressionAst.
+                    // Therefore we need to the VariableExpressionAst from its Child property.
+                    var assignmentVarAstAsConvertExpressionAst = assignmentAst.Left as ConvertExpressionAst;
+                    if (assignmentVarAstAsConvertExpressionAst != null && assignmentVarAstAsConvertExpressionAst.Child != null)
+                    {
+                        assignmentVarAst = assignmentVarAstAsConvertExpressionAst.Child as VariableExpressionAst;
+                    }
+                }
+
                 if (assignmentVarAst != null)
                 {
                     // Ignore if variable is global or environment variable or scope is function

Tests/Rules/UseDeclaredVarsMoreThanAssignments.tests.ps1

@@ -38,6 +38,12 @@ function MyFunc2() {
             Should Be 1
         }
 
+        It "flags strongly typed variables" {
+            Invoke-ScriptAnalyzer -ScriptDefinition '[string]$s=''mystring''' -IncludeRule $violationName  | `
+            Get-Count | `
+            Should Be 1
+        }
+
         It "does not flag `$InformationPreference variable" {
             Invoke-ScriptAnalyzer -ScriptDefinition '$InformationPreference=Stop' -IncludeRule $violationName  | `
             Get-Count | `