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>

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
+        }
+    }
 }