fix(types): correct intersection, indexedAccess, and add predicate/templateLiteral

[sujalgoel]

Problem

Four bugs in plugins/theme/partials/types.mjs:

1. intersection rendered with | instead of &

The union and intersection cases shared one return union(type.types) call. union() defaults to |, so A & B was rendered as {A|B} — same as a union type.

2. indexedAccess lost the index type

optional and indexedAccess were merged under one case using type.elementType ?? type.objectType. IndexedAccessType has no elementType field, so the fallback always resolved to objectType alone — dropping the index type entirely.

• T[K] was rendered as {T}, now renders as {T[K]}

3. Missing predicate case

TypeDoc emits predicate types for type guard signatures like x is string and asserts x is string. These fell through to the default branch and returned type.name ?? 'unknown' — dropping the target type.

4. Missing templateLiteral case

Template literal types (`prefix_${string}`) also fell through to the default branch.

Fix

• Split union and intersection into separate cases; intersection passes '&' as the separator
• Split optional and indexedAccess into separate cases; indexedAccess renders as objectType[indexType]
• Add predicate case: (asserts?) name (is targetType?)
• Add templateLiteral case: `head${type1}span1${type2}span2...`

Verification

Pipeline (node generate-md.mjs) runs clean. Spot-checked output:

// Before
> **AssetInfo** = {KnownAssetInfo|Record<string, any>}

// After  
> **AssetInfo** = {KnownAssetInfo&Record<string, any>}

[avivkeller]

doc-kit doesn't yet support this. Please very that before sending a PR

[sujalgoel]

Checked this against doc-kit's normalizeTypes regex.

templateLiteral is the actual problem. ${...} puts { and } inside the type annotation, both excluded by [^<({})>], so {prefix_${string}} matches as {string} — wrong type, wrong link.

The other three are fine:

{A&B}          → matches (intersection fix)
{T[K]}         → matches (indexedAccess fix)
{x is string}  → matches (predicate)

Neither predicate nor templateLiteral show up in webpack's types.d.ts right now, so both are theoretical anyway. The intersection and indexedAccess fixes are for types already in the generated output: AssetInfo, getIncomingConnectionsByOriginModule, a few others.

Happy to either drop templateLiteral and ship the other three, or split the PR into two: bugs now, new type cases once doc-kit has support. Whatever works better for you.

[avivkeller]

Just because the normalizing regex matches the content of the {...}, doesn't mean they will be properly mapped to types.

[avivkeller]

We should just return the target, perhaps

[avivkeller]

Revert

[sujalgoel]

Got it. The theme fix needs doc-kit to support & and indexed access first. Is there a tracking issue for this, or should I open one?

[avivkeller]

Neither, if you'd like to open a PR to doc-kit, please do. A tracking issue isn't really needed, since it's more of a QoL thing