fix: address PR #60 review feedback

- SizeParser: wrap TB-suffix overflow in try/catch so callers get
  ArgumentException with the parameter name rather than OverflowException.
- New-PveVm/New-PveContainer: validate -DiskSize/-RootFsSize before
  ShouldProcess so typos like "512M" are rejected even with -WhatIf and
  even when the matching -DiskStorage/-RootFsStorage is omitted.
- Add Pester tests for the new DiskSize and RootFsSize validation paths,
  including a new New-PveContainer.Tests.ps1.
- Add SizeParserTests coverage for the TB overflow path.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/review/findings.json

@@ -2843,8 +2843,8 @@
       ],
       "resolution": {
         "scan_date": "2026-05-20",
-        "evidence": "Added SizeParser.NormalizeToGibibytes() which strips G/GB/T/TB suffixes (and rejects sub-GB units with a clear error). New-PveVm and New-PveContainer normalize -DiskSize and -RootFsSize through it before constructing the disk spec, so '32G' becomes '<storage>:32' on every storage type.",
-        "verified_by": "dotnet build + dotnet test (576 passed, 31 new SizeParserTests)"
+        "evidence": "Added SizeParser.NormalizeToGibibytes() which strips G/GB/T/TB suffixes, rejects sub-GB units with a clear error, and converts TB overflows to ArgumentException. New-PveVm and New-PveContainer normalize -DiskSize and -RootFsSize before ShouldProcess so typos are caught with -WhatIf, regardless of whether the matching -DiskStorage/-RootFsStorage was supplied.",
+        "verified_by": "dotnet build + dotnet test (577 passed, 32 SizeParserTests) + Pester (39 passed, new DiskSize/RootFsSize validation contexts)"
       }
     }
   ]

src/PSProxmoxVE.Core/Utilities/SizeParser.cs

@@ -59,7 +59,13 @@ namespace PSProxmoxVE.Core.Utilities
                 case "T":
                 case "TB":
                 case "TIB":
-                    gib = checked(num * 1024L);
+                    try { gib = checked(num * 1024L); }
+                    catch (OverflowException)
+                    {
+                        throw new ArgumentException(
+                            $"{parameterName} '{value}' is too large to represent in GiB.",
+                            parameterName);
+                    }
                     break;
                 default:
                     throw new ArgumentException(

src/PSProxmoxVE/Cmdlets/Containers/NewPveContainerCmdlet.cs

@@ -130,6 +130,13 @@ namespace PSProxmoxVE.Cmdlets.Containers
 
         protected override void ProcessRecord()
         {
+            // Validate -RootFsSize before ShouldProcess so typos like "512M" are rejected
+            // even with -WhatIf, and so the error is raised regardless of whether
+            // -RootFsStorage is also supplied.
+            string? rootFsSizeGib = null;
+            if (!string.IsNullOrEmpty(RootFsSize))
+                rootFsSizeGib = SizeParser.NormalizeToGibibytes(RootFsSize!, nameof(RootFsSize));
+
             if (!ShouldProcess($"Container on node '{Node}'", "New-PveContainer"))
                 return;
 
@@ -165,11 +172,8 @@ namespace PSProxmoxVE.Cmdlets.Containers
             if (!string.IsNullOrEmpty(RootFsStorage))
             {
                 var rootFsValue = RootFsStorage!;
-                if (!string.IsNullOrEmpty(RootFsSize))
-                {
-                    var sizeGib = SizeParser.NormalizeToGibibytes(RootFsSize!, nameof(RootFsSize));
-                    rootFsValue += $":{sizeGib}";
-                }
+                if (rootFsSizeGib != null)
+                    rootFsValue += $":{rootFsSizeGib}";
                 config["rootfs"] = rootFsValue;
             }
 

src/PSProxmoxVE/Cmdlets/Vms/NewPveVmCmdlet.cs

@@ -128,6 +128,13 @@ namespace PSProxmoxVE.Cmdlets.Vms
 
         protected override void ProcessRecord()
         {
+            // Validate -DiskSize before ShouldProcess so typos like "512M" are rejected
+            // even with -WhatIf, and so the error is raised regardless of whether
+            // -DiskStorage is also supplied.
+            string? diskSizeGib = null;
+            if (!string.IsNullOrEmpty(DiskSize))
+                diskSizeGib = SizeParser.NormalizeToGibibytes(DiskSize!, nameof(DiskSize));
+
             if (!ShouldProcess($"VM on node '{Node}'", "New-PveVm"))
                 return;
 
@@ -166,10 +173,9 @@ namespace PSProxmoxVE.Cmdlets.Vms
             if (!string.IsNullOrEmpty(OsType))
                 config["ostype"] = OsType!;
 
-            if (!string.IsNullOrEmpty(DiskStorage) && !string.IsNullOrEmpty(DiskSize))
+            if (!string.IsNullOrEmpty(DiskStorage) && diskSizeGib != null)
             {
-                var sizeGib = SizeParser.NormalizeToGibibytes(DiskSize!, nameof(DiskSize));
-                var diskValue = $"{DiskStorage}:{sizeGib}";
+                var diskValue = $"{DiskStorage}:{diskSizeGib}";
                 if (!string.IsNullOrEmpty(DiskFormat))
                     diskValue += $",format={DiskFormat}";
                 config["virtio0"] = diskValue;

tests/PSProxmoxVE.Core.Tests/Utilities/SizeParserTests.cs

@@ -76,5 +76,15 @@ namespace PSProxmoxVE.Core.Tests.Utilities
             Assert.Equal("DiskSize", ex.ParamName);
             Assert.Contains("DiskSize", ex.Message);
         }
+
+        [Fact]
+        public void NormalizeToGibibytes_TerabyteOverflow_ThrowsArgumentException()
+        {
+            // long.MaxValue with a T suffix overflows when multiplied by 1024.
+            var input = long.MaxValue.ToString(System.Globalization.CultureInfo.InvariantCulture) + "T";
+            var ex = Assert.Throws<ArgumentException>(() => SizeParser.NormalizeToGibibytes(input, "DiskSize"));
+            Assert.Equal("DiskSize", ex.ParamName);
+            Assert.Contains("too large", ex.Message, StringComparison.OrdinalIgnoreCase);
+        }
     }
 }

tests/PSProxmoxVE.Tests/Containers/New-PveContainer.Tests.ps1

@@ -0,0 +1,68 @@
+#Requires -Module Pester
+<#
+.SYNOPSIS
+    Pester 5 tests for New-PveContainer.
+    All tests are fully offline — no live Proxmox VE target is required.
+#>
+
+BeforeAll {
+    . $PSScriptRoot/../_TestHelper.ps1
+}
+
+Describe 'New-PveContainer' {
+
+    Context 'Command existence' {
+        It 'Should be available after module import' {
+            Get-Command 'New-PveContainer' -ErrorAction SilentlyContinue |
+                Should -Not -BeNullOrEmpty
+        }
+
+        It 'Should be a CmdletInfo (binary cmdlet)' {
+            (Get-Command 'New-PveContainer').CommandType | Should -Be 'Cmdlet'
+        }
+    }
+
+    Context 'ShouldProcess support' {
+        BeforeAll {
+            $script:Cmd = Get-Command 'New-PveContainer'
+        }
+
+        It 'Should support ShouldProcess (WhatIf parameter present)' {
+            $script:Cmd.Parameters.ContainsKey('WhatIf') | Should -BeTrue
+        }
+
+        It 'Should support ShouldProcess (Confirm parameter present)' {
+            $script:Cmd.Parameters.ContainsKey('Confirm') | Should -BeTrue
+        }
+    }
+
+    Context 'RootFsSize validation' {
+        # Validation runs before ShouldProcess so -WhatIf is enough to exercise it
+        # without an active session.
+
+        It 'Should reject sub-GB units (e.g. 512M)' {
+            { New-PveContainer -Node 'pve-node1' -RootFsStorage 'local-lvm' -RootFsSize '512M' -WhatIf -ErrorAction Stop } |
+                Should -Throw '*unsupported unit*'
+        }
+
+        It 'Should reject sub-GB units even when -RootFsStorage is omitted' {
+            { New-PveContainer -Node 'pve-node1' -RootFsSize '512M' -WhatIf -ErrorAction Stop } |
+                Should -Throw '*unsupported unit*'
+        }
+
+        It 'Should reject malformed input (e.g. 8.5G)' {
+            { New-PveContainer -Node 'pve-node1' -RootFsStorage 'local-lvm' -RootFsSize '8.5G' -WhatIf -ErrorAction Stop } |
+                Should -Throw '*not a valid size*'
+        }
+
+        It 'Should accept a bare integer with -WhatIf' {
+            { New-PveContainer -Node 'pve-node1' -RootFsStorage 'local-lvm' -RootFsSize '8' -WhatIf -ErrorAction Stop } |
+                Should -Not -Throw
+        }
+
+        It 'Should accept "8G" with -WhatIf' {
+            { New-PveContainer -Node 'pve-node1' -RootFsStorage 'local-lvm' -RootFsSize '8G' -WhatIf -ErrorAction Stop } |
+                Should -Not -Throw
+        }
+    }
+}

tests/PSProxmoxVE.Tests/Vms/New-PveVm.Tests.ps1

@@ -133,4 +133,39 @@ Describe 'New-PveVm' {
                 Should -Throw '*No active Proxmox VE session*'
         }
     }
+
+    Context 'DiskSize validation' {
+        # Validation runs before ShouldProcess so -WhatIf is enough to exercise it
+        # without an active session.
+
+        It 'Should reject sub-GB units (e.g. 512M)' {
+            { New-PveVm -Node 'pve-node1' -DiskStorage 'local-lvm' -DiskSize '512M' -WhatIf -ErrorAction Stop } |
+                Should -Throw '*unsupported unit*'
+        }
+
+        It 'Should reject sub-GB units even when -DiskStorage is omitted' {
+            { New-PveVm -Node 'pve-node1' -DiskSize '512M' -WhatIf -ErrorAction Stop } |
+                Should -Throw '*unsupported unit*'
+        }
+
+        It 'Should reject malformed input (e.g. 32.5G)' {
+            { New-PveVm -Node 'pve-node1' -DiskStorage 'local-lvm' -DiskSize '32.5G' -WhatIf -ErrorAction Stop } |
+                Should -Throw '*not a valid size*'
+        }
+
+        It 'Should accept a bare integer with -WhatIf' {
+            { New-PveVm -Node 'pve-node1' -DiskStorage 'local-lvm' -DiskSize '32' -WhatIf -ErrorAction Stop } |
+                Should -Not -Throw
+        }
+
+        It 'Should accept "32G" with -WhatIf' {
+            { New-PveVm -Node 'pve-node1' -DiskStorage 'local-lvm' -DiskSize '32G' -WhatIf -ErrorAction Stop } |
+                Should -Not -Throw
+        }
+
+        It 'Should accept "1T" with -WhatIf' {
+            { New-PveVm -Node 'pve-node1' -DiskStorage 'local-lvm' -DiskSize '1T' -WhatIf -ErrorAction Stop } |
+                Should -Not -Throw
+        }
+    }
 }