refactor: optimize maps (#997)

---------

Signed-off-by: Jan Kowalleck <[email protected]>

Author: jkowalleck

src/serialize/bomRefDiscriminator.ts

@@ -20,24 +20,24 @@ Copyright (c) OWASP Foundation. All Rights Reserved.
 import type { BomRef } from '../models'
 
 export class BomRefDiscriminator {
-  readonly #originalValues: ReadonlyMap<BomRef, string | undefined>
+  readonly #originalValues: ReadonlyArray<readonly [BomRef, string | undefined]>
 
   readonly #prefix: string
 
   constructor (bomRefs: Iterable<BomRef>, prefix: string = 'BomRef') {
-    this.#originalValues = new Map(
-      Array.from(bomRefs, r => [r, r.value])
-    )
+    this.#originalValues = Array.from(bomRefs, r => [r, r.value])
     this.#prefix = prefix
   }
 
   get prefix (): string {
     return this.#prefix
   }
 
-  /** Iterate over the bomRefs. */
-  [Symbol.iterator] (): IterableIterator<BomRef> {
-    return this.#originalValues.keys()
+  /** Iterate over the {@link BomRef}s. */
+  * [Symbol.iterator] (): IterableIterator<BomRef> {
+    for (const [bomRef] of this.#originalValues) {
+      yield bomRef
+    }
   }
 
   discriminate (): void {

src/spdx.ts

@@ -20,7 +20,7 @@ Copyright (c) OWASP Foundation. All Rights Reserved.
 import * as spdxExpressionParse from 'spdx-expression-parse'
 
 /* @ts-expect-error: TS6059 -- this works as long as the file/path is available in dist-package. */
-import { enum as _spdxSpecEnum } from '../res/schema/spdx.SNAPSHOT.schema.json' assert { type: 'json' }
+import { enum as _spdxSpecEnum } from '../res/schema/spdx.SNAPSHOT.schema.json' assert {type: 'json'}
 
 /**
  * One of the known SPDX licence identifiers.
@@ -33,9 +33,9 @@ export type SpdxId = string
 
 const spdxIds: ReadonlySet<SpdxId> = new Set(_spdxSpecEnum)
 
-const spdxLowerToActual: ReadonlyMap<string, SpdxId> = new Map(
+const spdxLowerToActual: Readonly<Record<string, SpdxId>> = Object.freeze(Object.fromEntries(
   _spdxSpecEnum.map(spdxId => [spdxId.toLowerCase(), spdxId])
-)
+))
 
 export function isSupportedSpdxId (value: SpdxId | any): value is SpdxId {
   return spdxIds.has(value)
@@ -44,7 +44,7 @@ export function isSupportedSpdxId (value: SpdxId | any): value is SpdxId {
 /** Try to convert a `string`-like to a valid/known {@link SpdxId}. */
 export function fixupSpdxId (value: string | any): SpdxId | undefined {
   return typeof value === 'string' && value.length > 0
-    ? spdxLowerToActual.get(value.toLowerCase())
+    ? spdxLowerToActual[value.toLowerCase()]
     : undefined
 }