typescript-extract-shared.ts

Detect a Svelte 5 reactivity rune from a variable or property initializer.

Inspects the AST since runes erase to their inner type after type-checking. Returns undefined for any non-rune expression. See the Reactivity enum in types.ts for the rationale on running this on every file regardless of extension.

Append a (call) or (construct) signature member to a declaration.

Captures the extraction logic shared by interface processing (extractTypeInfo) and type-alias property processing (extractTypeAliasProperties): type signature, parameters, generics, overloads, and TSDoc. The TSDoc source node is supplied by the caller — interfaces look it up in node.members (skipping TSDoc when no inline signature is declared, even if one is inherited), type aliases use sig.getDeclaration().

Extract modifier keywords from a node's modifiers.

Returns an array of modifier strings like ['public', 'readonly', 'static'].

Extract parameters from a TypeScript signature with TSDoc descriptions and default values.

Shared helper for extracting parameter information from both standalone functions and class methods/constructors.

Filter intersection type properties to exclude those from external sources, and extract type names for branches whose properties are all external.

Returns null for non-intersection types (caller should use unfiltered properties). For intersection types, returns filtered properties and external type names.

Per-property filtering works through utility types (Partial, Pick, Readonly) because TypeScript preserves original declaration sources on mapped type properties.

Extract line and column from a TypeScript node. Returns 1-based line and column numbers.

Infer declaration kind from symbol and node.

Maps TypeScript constructs to DeclarationKind: - Classes → 'class' - Functions (declarations, expressions, arrows) → 'function' - Interfaces → 'interface' - Type aliases → 'type' - Enums (regular and const) → 'enum' - Variables → 'variable' (unless function-valued → 'function')

Note: namespace re-exports (export * as ns from './x') have no inline declaration form in TypeScript and are caught upstream in analyzeExports via classifyNamespaceReExport. They never reach this function. A direct call here on a ValueModule symbol would fall through to 'variable' and leak typeof import("/abs/path") into the output — keep the namespace dispatch in analyzeExports.

Determine whether an intersection branch refers to a type whose declarations all live in external files (e.g., HTMLAttributes<HTMLDivElement> from svelte's d.ts). Inline object-literal branches and unrecognized node shapes return false (treated as local).

Parse a TypeScript generic type parameter declaration into structured info.

Populate the callable fields of a declaration or member from its call/construct signatures: typeSignature, parameters, overloads, and (unless includeReturn is false) returnType / returnDescription.

The shared core of every named-callable extractor — standalone functions, interface methods, class methods/constructors, and type-alias function properties. Callers differ in how they obtain signatures (symbol type, constructor declarations, property call signatures) and in their own try/catch + diagnostic kind, so those stay at the callsite; this captures only the identical projection from a resolved signature list onto the build target. No-op when signatures is empty.

Resolve the IntersectionTypeNode for a type node, walking through type alias indirection. Returns undefined when the underlying type is an intersection but no AST node is recoverable (rare — synthesized intersections).