Make AST & Symbol immutable to allow for multi-file support

[huydo862003]

Doc: Link

Problem

Context: Currently, the AST & Symbol is mutable:

• The Validator sets SyntaxNode.parent and SyntaxNode.symbol.
• The Binder sets SyntaxNode.referees and NodeSymbol.references.

Problems:

• Parsing is entirely local: That is, parsing only requires 1 file at a time & theoretically, the parsed AST can be reused if the file does not change.
• Validation is entirely local: It just validates the structure of the AST and registers symbols into the symbol table, it doesn’t require information from other files.
• Binding are global: It requires many files to resolve symbols, etc.

=> When a file changes, its binding phase reruns. Binding writes two things that span across files:

1. Symbols onto AST nodes — including nodes belonging to other files
2. References onto NodeSymbols — the symbol objects themselves are mutated

This means both ASTs and NodeSymbols become stale across the entire project, so everything must be discarded and re-parsed & re-validated from scratch — even files that didn't change.

The fix: make both ASTs and NodeSymbols immutable after parsing and validation, so a re-bind doesn't corrupt other files' data and unchanged files can be safely reused.

Solution:

• Move symbols outside the AST.
• The AST is immutable after parsing.

⇒ Allow us to reuse most ASTs if only 1 file changes.

Solution: Move symbol/referee mappings out of the AST so it becomes immutable after parsing -> ASTs can be reused across files when only one file changes.

Changes:

• Remove symbol and referee from SyntaxNode; introduce NodeToSymbolMap and NodeToRefereeMap on Analyzer
• Remove references from NodeSymbol; introduce NodeToReferencesMap on Analyzer
• Add bind method to Analyzer; move parent-node assignment to the parser (after gatherInvalid)
• Update binder, validator, interpreter, and LSP services to use the new maps

[github-actions]

Coverage Report

Commit: 8986732

Overall Coverage

Metric	Coverage
Lines	✅ 84.18% (5450/6474)
Statements	✅ 83.49% (5815/6965)
Functions	✅ 89.44% (1271/1421)
Branches	⚠️ 75.21% (3010/4002)

Package Coverage

Package	Lines	Statements	Functions	Branches
@dbml/dbml-cli	✅ 100.00%	✅ 100.00%	✅ 100.00%	✅ 100.00%
@dbml/dbml-connector	⚠️ 64.62%	⚠️ 64.36%	⚠️ 59.53%	⚠️ 59.09%
@dbml/dbml-core	N/A	N/A	N/A	N/A
@dbml/dbml-parse	✅ 87.52%	✅ 86.73%	✅ 93.58%	⚠️ 77.68%

⚠️ Coverage Warnings

The following packages have coverage below 80%:

• @dbml/dbml-connector: 64.62% line coverage

Files with Coverage Below 80%

@dbml/dbml-connector

9 file(s) below 80% coverage

File	Lines	Statements	Functions	Branches
src/connectors/bigquery/index.ts	0.00%	0.00%	0.00%	0.00%
src/utils/credential-loader.ts	0.00%	0.00%	0.00%	0.00%
src/utils/helpers.ts	0.00%	0.00%	0.00%	0.00%
src/connectors/snowflake/index.ts	10.56%	10.31%	0.00%	0.00%
src/utils/parseSchema.ts	46.15%	42.85%	28.57%	27.27%
src/connectors/connector.ts	66.66%	66.66%	100.00%	57.14%
src/connectors/oracle/tables.ts	71.25%	67.39%	100.00%	56.96%
src/connectors/oracle/index.ts	80.00%	80.76%	100.00%	25.00%
src/connectors/oracle/utils.ts	85.71%	85.71%	100.00%	71.42%

@dbml/dbml-parse

40 file(s) below 80% coverage

File	Lines	Statements	Functions	Branches
src/compiler/queries/container/scope.ts	0.00%	0.00%	0.00%	0.00%
src/services/diagnostics/provider.ts	0.00%	0.00%	0.00%	0.00%
src/core/interpreter/elementInterpreter/project.ts	51.42%	51.42%	100.00%	36.36%
src/core/interpreter/records/utils/data/sqlTypes.ts	56.25%	58.82%	75.00%	46.55%
src/core/analyzer/symbol/utils.ts	56.52%	56.52%	100.00%	50.00%
src/core/analyzer/analyzer.ts	61.53%	60.00%	57.14%	0.00%
src/core/analyzer/binder/elementBinder/note.ts	62.50%	64.70%	83.33%	50.00%
src/compiler/queries/utils.ts	64.83%	65.95%	88.88%	47.43%
src/core/interpreter/records/utils/data/values.ts	65.13%	57.14%	72.72%	50.37%
src/compiler/queries/token.ts	66.66%	66.66%	66.66%	100.00%
src/compiler/queries/parse.ts	70.00%	70.00%	66.66%	100.00%
src/core/parser/utils.ts	71.71%	72.43%	100.00%	78.98%
src/core/analyzer/binder/elementBinder/enum.ts	72.22%	73.68%	100.00%	62.50%
src/core/analyzer/validator/elementValidators/indexes.ts	73.33%	74.07%	90.90%	57.69%
src/core/analyzer/validator/elementValidators/note.ts	74.50%	72.72%	76.92%	68.75%
src/core/analyzer/binder/elementBinder/ref.ts	75.75%	77.14%	90.90%	70.00%
src/core/analyzer/symbol/symbolIndex.ts	76.92%	77.50%	92.85%	50.00%
src/core/analyzer/binder/elementBinder/project.ts	77.77%	78.94%	100.00%	50.00%
src/core/analyzer/validator/elementValidators/project.ts	78.12%	78.78%	100.00%	56.25%
src/core/analyzer/utils.ts	78.50%	77.06%	88.88%	77.55%
src/core/utils.ts	78.57%	77.41%	80.00%	60.71%
src/core/analyzer/validator/elementValidators/records.ts	79.45%	80.00%	93.75%	74.19%
src/core/analyzer/binder/elementBinder/indexes.ts	79.54%	78.26%	90.90%	68.18%
src/core/analyzer/validator/elementValidators/checks.ts	79.62%	81.03%	93.75%	71.87%
src/core/analyzer/binder/elementBinder/tableGroup.ts	80.00%	80.64%	100.00%	50.00%
src/core/interpreter/records/utils/constraints/pk.ts	82.00%	80.00%	92.30%	54.54%
src/services/suggestions/utils.ts	82.35%	76.78%	92.85%	70.37%
src/core/analyzer/binder/elementBinder/records.ts	82.97%	83.50%	93.75%	71.42%
src/compiler/queries/container/token.ts	83.33%	85.71%	100.00%	75.00%
src/core/analyzer/validator/elementValidators/tablePartial.ts	83.52%	80.82%	87.23%	64.28%
src/core/analyzer/binder/elementBinder/tablePartial.ts	86.00%	86.53%	100.00%	69.23%
src/core/parser/parser.ts	87.08%	87.23%	100.00%	79.25%
src/services/suggestions/recordRowSnippet.ts	89.28%	85.29%	100.00%	78.00%
src/compiler/queries/symbol.ts	92.00%	92.59%	100.00%	78.57%
__tests__/utils/compiler.ts	92.92%	92.75%	100.00%	70.32%
__tests__/utils/testHelpers.ts	93.54%	94.28%	75.00%	88.09%
src/core/interpreter/elementInterpreter/sticky_note.ts	95.00%	95.23%	100.00%	66.66%
src/core/interpreter/records/utils/constraints/unique.ts	96.15%	93.93%	100.00%	66.66%
src/core/analyzer/symbol/symbolTable.ts	100.00%	100.00%	100.00%	75.00%
src/services/definition/provider.ts	100.00%	94.44%	100.00%	70.00%