fix: add parentheses required by specific grammar positions#136
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MathiasWP wants to merge 9 commits into
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fix: add parentheses required by specific grammar positions#136MathiasWP wants to merge 9 commits into
MathiasWP wants to merge 9 commits into
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… constants Derives UNARY/BINARY/LOGICAL precedence from EXPRESSIONS_PRECEDENCE so the checks in needs_parens can never drift out of sync with the table, which is what caused sveltejs#131 (a stale `13`/`12` literal). Behavior is unchanged.
Three classes of bug in the same family as sveltejs#131 (dropped parentheses that change meaning or produce invalid output): - nested same-sign unary operators were glued together. `-(-a)` printed as `--a` (the decrement operator) — valid but wrong; `-(--a)` printed as `---a` — invalid. Fixed by emitting a space when a unary `+`/`-` is followed by a unary/prefix-update of the same sign. - the optional-chaining boundary (ChainExpression) was dropped. `(a?.b)()` printed as `a?.b()`, silently changing short-circuit behaviour; `new (a?.b)()` and the tagged-template form became invalid. Fixed by parenthesizing a ChainExpression used as a callee/object/tag. - `await` as the left operand of `**` lost its parentheses. `(await a) ** b` printed as the SyntaxError `await a ** b`. Fixed by covering AwaitExpression in the `**` left-operand check. Adds test/paren-correctness.test.js covering all three plus a control that genuine single optional chains are not over-parenthesized.
Remove UNARY_PRECEDENCE/BINARY_PRECEDENCE/LOGICAL_PRECEDENCE consts and reference EXPRESSIONS_PRECEDENCE directly at each use site.
Some positions require parentheses that esrap was dropping, producing invalid
output or changing meaning:
- the `extends` super-class (class heritage) — class A extends (B || C) {}
- a tagged-template tag — (x || y)`tpl`
- a decorator expression — @(a ? b : c)
- an angle-bracket type assertion as the left of ** — (<T>x) ** y
- an expression statement starting with {, function, or class — ({} + []),
(class {}), (function(){})`x` — via a precedence-aware left-spine walk that
mirrors the parenthesization the visitors already apply (so already-safe
forms like ({}).x are not double-wrapped)
Adds test/required-parens-positions.test.js.
🦋 Changeset detectedLatest commit: b90d727 The changes in this PR will be included in the next version bump. This PR includes changesets to release 1 package
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Stacked on #134 (builds on its
needs_parenschanges — the diff narrows to just this branch once #134 lands).Adds parentheses that the position requires but esrap was dropping (invalid output or changed meaning):
extendssuper-class —class A extends (B || C) {}(x || y)`tpl`@(a ? b : c)**—(<T>x) ** y{,function, orclass—({} + []),(class {}),(function(){})`x`