From d350e8dbde517b9b35ea6e18625e5a0ea80506c3 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Sun, 8 Mar 2026 04:39:19 +0000
Subject: [PATCH] Add fromZipData method for pre-loaded ZIP data
 (ArrayBuffer/Uint8Array)

Split the binary data path out of fromZip into a dedicated fromZipData
static method. fromZip now fetches the data then delegates to fromZipData,
keeping a single code path with no typeof branching in the init logic.

https://claude.ai/code/session_01WN4mwTdgg65ooAtV8K9HP2
---
 CHANGELOG.md      |  3 ++-
 README.md         |  3 ++-
 src/gtfs-sqljs.ts | 50 ++++++++++++++++++++++-------------------------
 3 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index aa7cb43..84a2fb4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,8 @@
 
 ## Upcoming release
 
--
+- Add `GtfsSqlJs.fromZipData(zipData, options?)` static method for loading from pre-loaded ZIP data (`ArrayBuffer` or `Uint8Array`)
+- Keep `GtfsSqlJs.fromZip(zipPath, options?)` strictly typed as `string` for paths/URLs
 
 ## 0.2.2
 
diff --git a/README.md b/README.md
index 2385606..1f9708a 100644
--- a/README.md
+++ b/README.md
@@ -97,7 +97,8 @@ Full API documentation: [API Reference](https://sysdevrun.github.io/gtfs-sqljs/d
 
 ### Static Methods
 
-- `GtfsSqlJs.fromZip(zipPath, options?)` - Create instance from GTFS ZIP file
+- `GtfsSqlJs.fromZip(zipPath, options?)` - Create instance from GTFS ZIP file path or URL
+- `GtfsSqlJs.fromZipData(zipData, options?)` - Create instance from pre-loaded GTFS ZIP data (`ArrayBuffer` or `Uint8Array`)
 - `GtfsSqlJs.fromDatabase(database, options?)` - Create instance from existing database
 
 ### Instance Methods
diff --git a/src/gtfs-sqljs.ts b/src/gtfs-sqljs.ts
index 736b101..3b10d6d 100644
--- a/src/gtfs-sqljs.ts
+++ b/src/gtfs-sqljs.ts
@@ -147,14 +147,27 @@ export class GtfsSqlJs {
   private constructor() {}
 
   /**
-   * Create GtfsSqlJs instance from GTFS ZIP file
+   * Create GtfsSqlJs instance from GTFS ZIP file path or URL
    */
   static async fromZip(
     zipPath: string,
     options: Omit<GtfsSqlJsOptions, 'zipPath' | 'database'> = {}
+  ): Promise<GtfsSqlJs> {
+    const zipData = await fetchZip(zipPath, options.onProgress);
+    return GtfsSqlJs.fromZipData(zipData, options, zipPath);
+  }
+
+  /**
+   * Create GtfsSqlJs instance from pre-loaded GTFS ZIP data
+   * @param source - Optional original path/URL, used for cache key generation and metadata
+   */
+  static async fromZipData(
+    zipData: ArrayBuffer | Uint8Array,
+    options: Omit<GtfsSqlJsOptions, 'zipPath' | 'database'> = {},
+    source?: string
   ): Promise<GtfsSqlJs> {
     const instance = new GtfsSqlJs();
-    await instance.initFromZip(zipPath, options);
+    await instance.initFromZipData(zipData, options, source);
     return instance;
   }
 
@@ -171,9 +184,10 @@ export class GtfsSqlJs {
   }
 
   /**
-   * Initialize from ZIP file
+   * Initialize from pre-loaded ZIP data
+   * @param source - Optional original path/URL, used for cache key generation and metadata
    */
-  private async initFromZip(zipPath: string, options: Omit<GtfsSqlJsOptions, 'zipPath' | 'database'>): Promise<void> {
+  private async initFromZipData(zipData: ArrayBuffer | Uint8Array, options: Omit<GtfsSqlJsOptions, 'zipPath' | 'database'>, source?: string): Promise<void> {
     const onProgress = options.onProgress;
     const {
       cache: userCache,
@@ -203,15 +217,6 @@ export class GtfsSqlJs {
         message: 'Checking cache...',
       });
 
-      // Fetch raw zip data for checksum (only if zipPath is a string)
-      let zipData: ArrayBuffer;
-      if (typeof zipPath === 'string') {
-        zipData = await fetchZip(zipPath, onProgress);
-      } else {
-        // zipPath is already ArrayBuffer or Uint8Array
-        zipData = zipPath as ArrayBuffer;
-      }
-
       // Calculate filesize
       const filesize = zipData.byteLength;
 
@@ -224,7 +229,7 @@ export class GtfsSqlJs {
         LIB_VERSION,
         cacheVersion,
         filesize,
-        typeof zipPath === 'string' ? zipPath : undefined,
+        source,
         skipFiles
       );
 
@@ -307,7 +312,7 @@ export class GtfsSqlJs {
         checksum,
         version: cacheVersion,
         timestamp: Date.now(),
-        source: typeof zipPath === 'string' ? zipPath : undefined,
+        source,
         size: dbBuffer.byteLength,
         skipFiles,
       });
@@ -326,16 +331,7 @@ export class GtfsSqlJs {
       return;
     }
 
-    // No cache - use normal loading flow
-    // Fetch zip data
-    let zipData: ArrayBuffer;
-    if (typeof zipPath === 'string') {
-      zipData = await fetchZip(zipPath, onProgress);
-    } else {
-      zipData = zipPath as ArrayBuffer;
-    }
-
-    // Load from zip data
+    // No cache - load directly from zip data
     await this.loadFromZipData(zipData, options, onProgress);
 
     onProgress?.({
@@ -351,11 +347,11 @@ export class GtfsSqlJs {
   }
 
   /**
-   * Helper method to load GTFS data from zip data (ArrayBuffer)
+   * Helper method to load GTFS data from zip data
    * Used by both cache-enabled and cache-disabled paths
    */
   private async loadFromZipData(
-    zipData: ArrayBuffer,
+    zipData: ArrayBuffer | Uint8Array,
     options: Omit<GtfsSqlJsOptions, 'zipPath' | 'database'>,
     onProgress?: ProgressCallback
   ): Promise<void> {