[darshjoshi]

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Type of change

• Bug fix (non-breaking change which fixes an issue)

Changes To Core Features:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your core changes, as applicable?
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Description

number_exponent_operation renders ({lhs} ** {rhs}) as is. JavaScript doesn't allow a unary expression as the base of ** (-2 ** 2 is a SyntaxError, unlike Python where it means -(2 ** 2)), so when the base is a negative literal or a negated var the compiled page doesn't build. For example (-State.velocity) ** 2 renders as (-(…velocity…) ** 2) and rx.Var.create(-2) ** State.n as (-2 ** …n…).

The base is now parenthesized when it starts with a unary operator, so those become ((-(…velocity…)) ** 2) and ((-2) ** …n…). Everything else renders exactly as before ((1 ** 2), (x ** -1), and -(x ** 2) from -x ** 2), so no existing snapshot changes.

Before / After with a one-page app, rx.text("squared: ", (-State.velocity) ** 2), running reflex export --frontend-only:

# before (main)
error: Build failed with 1 error:
[builtin:vite-transform] A unary expression with the '-' operator cannot
be used as the left operand of an exponentiation expression
    ╭─[ app_components/powapp/powapp.jsx:21:10 ]
 21 │ (-(reflex___state____state__powapp___powapp____state.velocity_rx_state_) ** 2)
    │ Help: Wrap the unary expression in parentheses to make the precedence explicit
exit=1

# after
Creating Production Build:  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 100% 4/4
exit=0

I also ran the rendered expressions through Node and they match Python: ((-(x)) ** 2) is 9, ((-2) ** x) is -8, ((-2.5) ** 2) is 6.25 for x = 3.

test_exponent_parenthesizes_a_unary_base covers the negative-literal and negated-var bases and the cases that must stay unwrapped, and fails on main with '(-2 ** 3)' == '((-2) ** 3)'. tests/units passes (11965 passed), along with ruff and pyright on the changed files.

[cubic-dev-ai]

No issues found across 2 files

_{View guided diff | Re-trigger cubic}

[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge; no new blocking issues were found.

Summary

Fixes JavaScript build errors when a negative number or negated variable is raised to a power.

• Power expressions now group unary bases before exponentiation.

_{Reviews (6) · Last reviewed commit: "Merge branch 'main' into fix-negative-ex..." · Reviewed by Greptile}

[codspeed]

Merging this PR will not alter performance

1 warning

⚠️ 13 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

✅ 148 untouched benchmarks

---

_{Comparing darshjoshi:fix-negative-exponent-base (3e82720) with main (be0c685)}

[cubic-dev-ai]

All reported issues were addressed across 2 files (changes from recent commits).

<sub>Tip: Review your code locally with the cubic CLI to iterate faster.

View guided diff | Re-trigger cubic</sub>

[masenf]

thanks, appreciate the fix