Fix: Validate subscription before execution to prevent crash on missing credentials

src/Commands/AccumulatedCost/AccumulatedCostCommand.cs

@@ -27,6 +27,22 @@ public AccumulatedCostCommand(ICostRetriever costRetriever)
 
     public override ValidationResult Validate(CommandContext context, AccumulatedCostSettings settings)
     {
+        // Check if we have any scope parameters when the scope requires subscription
+        if (settings.GetScope.IsSubscriptionBased && !settings.Subscription.HasValue)
+        {
+            // Try to get subscription from Azure CLI
+            try
+            {
+                var subscriptionId = Guid.Parse(AzCommand.GetDefaultAzureSubscriptionId());
+                settings.Subscription = subscriptionId;
+            }
+            catch (Exception)
+            {
+                // If we can't get the subscription from Azure CLI, return an error
+                return ValidationResult.Error("No subscription ID provided and unable to retrieve from Azure CLI. Please specify a subscription ID using -s or --subscription, or login to Azure CLI using 'az login'. Use --help for more information.");
+            }
+        }
+
         // Automatically set timeframe to Custom if both from and to dates are provided
         settings.ApplyAutoTimeframe();
 
@@ -51,32 +67,9 @@ public override async Task<int> ExecuteAsync(CommandContext context, Accumulated
         _costRetriever.CostApiAddress = settings.CostApiAddress;
         _costRetriever.HttpTimeout = TimeSpan.FromSeconds(settings.HttpTimeout);
 
-        // Get the subscription ID from the settings
+        // Get the subscription ID from the settings (already validated and set in Validate method)
         var subscriptionId = settings.Subscription;
 
-        if (subscriptionId.HasValue == false && (settings.GetScope.IsSubscriptionBased))
-        {
-            // Get the subscription ID from the Azure CLI
-            try
-            {
-                if (settings.Debug)
-                    AnsiConsole.WriteLine("No subscription ID specified. Trying to retrieve the default subscription ID from Azure CLI.");
-
-                subscriptionId = Guid.Parse(AzCommand.GetDefaultAzureSubscriptionId());
-
-                if (settings.Debug)
-                    AnsiConsole.WriteLine($"Default subscription ID retrieved from az cli: {subscriptionId}");
-
-                settings.Subscription = subscriptionId;
-            }
-            catch (Exception e)
-            {
-                AnsiConsole.WriteException(new ArgumentException(
-                    "Missing subscription ID. Please specify a subscription ID or login to Azure CLI.", e));
-                return -1;
-            }
-        }
-
         AccumulatedCostDetails accumulatedCost = null;
 
         Subscription subscription = null;

tests/AzureCostCli.Tests/Commands/AdditionalCommandTests.cs

@@ -26,6 +26,7 @@ public void Validate_WithCustomTimeframeAndValidDates_ReturnsSuccess()
         // Arrange
         var settings = new AccumulatedCostSettings
         {
+            Subscription = Guid.NewGuid(),
             Timeframe = TimeframeType.Custom,
             From = new DateOnly(2023, 1, 1),
             To = new DateOnly(2023, 1, 31)
@@ -45,6 +46,7 @@ public void Validate_WithCustomTimeframeAndFromDateAfterToDate_ReturnsError()
         // Arrange
         var settings = new AccumulatedCostSettings
         {
+            Subscription = Guid.NewGuid(),
             Timeframe = TimeframeType.Custom,
             From = new DateOnly(2023, 1, 31),
             To = new DateOnly(2023, 1, 1)
@@ -65,6 +67,7 @@ public void Validate_WithNonCustomTimeframe_ReturnsSuccess()
         // Arrange
         var settings = new AccumulatedCostSettings
         {
+            Subscription = Guid.NewGuid(),
             Timeframe = TimeframeType.MonthToDate
         };
         var context = CreateCommandContext();
@@ -82,6 +85,7 @@ public void Validate_WithBothFromAndToDates_AutomaticallySetsTimeframeToCustom()
         // Arrange
         var settings = new AccumulatedCostSettings
         {
+            Subscription = Guid.NewGuid(),
             Timeframe = TimeframeType.BillingMonthToDate, // Not Custom initially
             From = new DateOnly(2023, 1, 1),
             To = new DateOnly(2023, 1, 31)
@@ -102,6 +106,7 @@ public void Validate_WithOnlyFromDate_DoesNotSetTimeframeToCustom()
         // Arrange
         var settings = new AccumulatedCostSettings
         {
+            Subscription = Guid.NewGuid(),
             Timeframe = TimeframeType.BillingMonthToDate,
             From = new DateOnly(2023, 1, 1)
             // To is not set
@@ -122,6 +127,7 @@ public void Validate_WithAutoCustomAndInvalidDates_ReturnsError()
         // Arrange
         var settings = new AccumulatedCostSettings
         {
+            Subscription = Guid.NewGuid(),
             Timeframe = TimeframeType.BillingMonthToDate, // Will be auto-set to Custom
             From = new DateOnly(2023, 1, 31), // From after To
             To = new DateOnly(2023, 1, 1)
@@ -144,6 +150,62 @@ public void Constructor_SetsUpOutputFormatters()
         command.ShouldNotBeNull();
     }
 
+    [Fact]
+    public void Validate_WithNoSubscriptionAndNoAzureCLI_ReturnsError()
+    {
+        // Arrange
+        var settings = new AccumulatedCostSettings
+        {
+            Subscription = null // No subscription provided
+        };
+        var context = CreateCommandContext();
+
+        // Act
+        var result = _command.Validate(context, settings);
+
+        // Assert
+        result.Successful.ShouldBeFalse();
+        result.Message.ShouldContain("No subscription ID provided");
+        result.Message.ShouldContain("--help");
+    }
+
+    [Fact]
+    public void Validate_WithSubscription_ReturnsSuccess()
+    {
+        // Arrange
+        var settings = new AccumulatedCostSettings
+        {
+            Subscription = Guid.NewGuid(),
+            Timeframe = TimeframeType.BillingMonthToDate
+        };
+        var context = CreateCommandContext();
+
+        // Act
+        var result = _command.Validate(context, settings);
+
+        // Assert
+        result.Successful.ShouldBeTrue();
+    }
+
+    [Fact]
+    public void Validate_WithBillingAccountAndNoSubscription_ReturnsSuccess()
+    {
+        // Arrange
+        var settings = new AccumulatedCostSettings
+        {
+            Subscription = null,
+            BillingAccountId = "12345",
+            Timeframe = TimeframeType.BillingMonthToDate
+        };
+        var context = CreateCommandContext();
+
+        // Act
+        var result = _command.Validate(context, settings);
+
+        // Assert
+        result.Successful.ShouldBeTrue();
+    }
+
     private static CommandContext CreateCommandContext()
     {
         var remainingArguments = Mock.Of<IRemainingArguments>();