Function classifyStructure

packages/tools/api-diff/src/Diff.ts:192–332

(match: Match)

  )

const classifyStructure = (match: Match): ReadonlyArray<ApiChange> => {
  const base = match.base
  const head = match.head
  const changes: Array<ApiChange> = []
  if (base.bucket !== head.bucket) {
    changes.push(makeChange("bucket-changed", match, { before: base.bucket, after: head.bucket }))
  }
  if (base.declarationKind !== head.declarationKind) {
    changes.push(makeChange("declaration-kind-changed", match, {
      before: base.declarationKind,
      after: head.declarationKind
    }))
  }

  const baseDeclarations = base.declarations
  const headDeclarations = head.declarations
  const baseSignatures = baseDeclarations.filter((declaration) =>
    declaration.kind === "function" || declaration.kind === "method"
  )
  const headSignatures = headDeclarations.filter((declaration) =>
    declaration.kind === "function" || declaration.kind === "method"
  )
  if (headSignatures.length > baseSignatures.length) {
    changes.push(makeChange("overload-added", match, {
      before: baseSignatures.length,
      after: headSignatures.length
    }))
  } else if (headSignatures.length < baseSignatures.length) {
    changes.push(makeChange("overload-removed", match, {
      before: baseSignatures.length,
      after: headSignatures.length
    }))
  } else if (
    baseSignatures.length > 1 &&
    stableJson(baseSignatures.map(declarationHash).sort()) === stableJson(headSignatures.map(declarationHash).sort()) &&
    stableJson(baseSignatures.map(declarationHash)) !== stableJson(headSignatures.map(declarationHash))
  ) {
    changes.push(makeChange("overload-reordered", match))
  }

  const comparedSignatures = Math.min(baseSignatures.length, headSignatures.length)
  for (let index = 0; index < comparedSignatures; index++) {
    const before = baseSignatures[index]!
    const after = headSignatures[index]!
    const beforeParameters = before.parameters ?? []
    const afterParameters = after.parameters ?? []
    if (afterParameters.length > beforeParameters.length) {
      changes.push(makeChange("parameter-added", match, {
        overload: index,
        before: beforeParameters,
        after: afterParameters
      }, String(index)))
    } else if (afterParameters.length < beforeParameters.length) {
      changes.push(makeChange("parameter-removed", match, {
        overload: index,
        before: beforeParameters,
        after: afterParameters
      }, String(index)))