pwsh: encodeEnvVarsForPowerShell rejects Windows-standard env var names like ProgramFiles(x86), breaking wsh token on every pwsh block #3481

Description

encodeEnvVarsForPowerShell in pkg/util/shellutil/tokenswap.go validates every environment variable name against the strict POSIX-identifier regex ^[A-Za-z_][A-Za-z0-9_]*$ (IsValidEnvVarName in pkg/util/shellutil/shellquote.go), and this validation is applied unconditionally to ALL shells in EncodeEnvVarsForShell, including pwsh.

Windows always defines environment variables containing parentheses, e.g. ProgramFiles(x86) and CommonProgramFiles(x86). These names fail the regex, so encodeEnvVarsForPowerShell returns:

invalid env var name: "ProgramFiles(x86)"

EncodeEnvVarsForShell propagates this as a hard error, which aborts the entire token exchange, not just the one offending variable.

Why this matters

This is not a cosmetic edge case, it fires on essentially every PowerShell block launch on Windows. Wave's own bundled pwsh shell-integration script (wavepwsh.ps1, generated for the pwsh shell type) runs:

wsh token $env:WAVETERM_SWAPTOKEN pwsh 2>$null

The 2>$null silently swallows the error, so the failure is invisible in normal use, but the entire env-var/init-script exchange for that block never runs.

Root cause

$env:ProgramFiles(x86) = "..." is invalid PowerShell syntax (parens are parsed as a command invocation), so the strict validator was presumably written to avoid emitting that. But PowerShell has a second, valid assignment form for exactly this case:

${env:ProgramFiles(x86)} = "..."

The ${env:NAME} delimited form tolerates parentheses (and most other characters) in the variable name. The validator doesn't need to reject these names for PowerShell at all, it just needs to emit the delimited form instead of the bare $env:NAME form.

Suggested fix

Scope the fix to encodeEnvVarsForPowerShell only (leave encodeEnvVarsForBash / encodeEnvVarsForFish untouched, the POSIX identifier rule is correct there):

• Emit ${env:%s} = %s instead of $env:%s = %s.
• Only reject a name if it's structurally impossible to express in that form (empty, or contains a literal }), rather than requiring a POSIX identifier.

Environment

• Wave Terminal / wsh version: v0.14.5 (also present in current main as of this report, pkg/util/shellutil/tokenswap.go is unchanged on that path)
• OS: Windows 11
• Shell: pwsh (PowerShell 7)

Repro

package main

import (
	"fmt"
	"github.com/wavetermdev/waveterm/pkg/util/shellutil"
)

func main() {
	env := map[string]string{"ProgramFiles(x86)": `C:\Program Files (x86)`}
	_, err := shellutil.EncodeEnvVarsForShell("pwsh", env)
	fmt.Println(err) // invalid env var name: "ProgramFiles(x86)"
}

Or from a shell with any real Windows environment:

wsh token <valid-swap-token> pwsh
# Error: error encoding env vars: invalid env var name: "ProgramFiles(x86)"