[sanjevirau]

Fixes #229: 25 of its 26 recorded compile-error answers now match the official emulator exactly. The last, version/one, needs version 1 of the rules language and is listed under #247.

Errors after the first

The official parser is ANTLR's, and its default error strategy recovers and goes on reporting; Firenook stopped at the first problem. The parser now recovers as the recordings show:

• each rule knows what may follow it, and after an error skips to one of those tokens; recovering twice at one token in one state skips one more, so every recovery consumes input or stops;
• after an error nothing more is reported until a token matches, except the grammar's own messages, and an unwanted token is reported without a recovery (two lines at one position, as the official answers have);
• at a service, function, match and path segment it looks ahead as the official parser does, so a broken match is read again as a path missing its keyword;
• a missing token is reported with what fitted where a rule could have ended;
• errors are listed by position, then message;
• the lexer reads match paths segment by segment, // is a comment even in a path, and the word after service is its name. An interpolation's text ($(…)) is lexed as the expression it is, so /a/$(/b/c) stays one path (the first CI run caught this, in rules-document-paths-v1 case interpolating-a-literal).

The nesting bounds (240 expression levels, 128 match levels) and their tests are unchanged.

Warnings

crates/rules-engine/src/issues.rs gives the official compiler's warnings the recordings show: an unknown service or method, request and resource where no allow defines them, and parameters and lets nothing reads. A reload that compiles answers them as issues, and a refusal lists them beside its errors.

As officially, rules of an unknown service now compile and govern nothing (every request is denied), and an unknown method grants nothing; they used to be refused. So that a misspelling still shows, each warning is logged as the official CLI logs it after a reload (firestore.rules:2:9 - WARNING Invalid service name: cloud.firestor.), for Firestore and Storage rules, on a reload and also at start, where the official CLI says nothing. Checked against firebase-tools 15.35.0 with a misspelled service: it starts, denies a client write (403) and prints those lines on a reload; this branch does the same, and prints them at start.

Checked

• The compile-error replay: 119 of 120 recordings match; version/one is listed under Rules: rules_version 1 is evaluated as version 2 #247 and the ledger gate passes both ways.
• Beyond the recordings, 2,220 sources run through both emulators (single-token changes to three rulesets, plus the 120): on the 2,104 the official emulator refuses, the answers are now identical for 1,855 (800 before), and no source that matched before differs now.
• Real rulesets compile as before, with no warnings or one.
• The client replays (rules paths and document names, Storage native clients, kindless queries, listen resume, contributed rooms, write races) pass.
• The Rust gate (fmt, Clippy, every workspace test) passes on Linux on top of current main.
• Compiling the frozen 50 KB ruleset: about 0.86 ms before, 0.98 ms after (release build, one machine).

🤖 Generated with Claude Code

https://claude.ai/code/session_01APfZAFCQzCmvhJqWKMT47g