✨ Add Blob support to PlatformFile on Web (JS/Wasm)

filekit-core/src/webMain/kotlin/io/github/vinceglb/filekit/PlatformFile.web.kt

@@ -12,7 +12,11 @@ import kotlinx.serialization.Serializable
 import org.khronos.webgl.ArrayBuffer
 import org.khronos.webgl.Uint8Array
 import org.khronos.webgl.get
+import org.khronos.webgl.set
+import org.w3c.files.Blob
+import org.w3c.files.FilePropertyBag
 import org.w3c.files.FileReader
+import kotlin.collections.forEachIndexed
 import kotlin.coroutines.resume
 import kotlin.coroutines.resumeWithException
 import kotlin.js.ExperimentalWasmJsInterop
@@ -31,7 +35,22 @@ public actual data class PlatformFile(
 ) {
     public actual override fun toString(): String = path
 
-    public actual companion object
+    public actual companion object {
+        /**
+         * Creates a [PlatformFile] from a browser [Blob].
+         *
+         * Since a browser [File] is a subtype of [Blob], it can also be passed directly.
+         */
+        @OptIn(ExperimentalWasmJsInterop::class)
+        public operator fun invoke(blob: Blob, name: String): PlatformFile {
+            val file = BrowserFile(
+                fileBits = listOf(blob.unsafeCast<JsAny>()).toJsArray(),
+                fileName = name,
+                options = FilePropertyBag(type = blob.type),
+            )
+            return PlatformFile(webFile = WebFile.FileWrapper(file = file))
+        }
+    }
 }
 
 public actual val PlatformFile.name: String

filekit-core/src/webTest/kotlin/io/github/vinceglb/filekit/PlatformFileWebTest.kt

@@ -4,6 +4,8 @@ import io.github.vinceglb.filekit.exceptions.FileKitException
 import io.github.vinceglb.filekit.mimeType.MimeType
 import io.github.vinceglb.filekit.utils.createTestFile
 import kotlinx.coroutines.test.runTest
+import org.w3c.files.Blob
+import org.w3c.files.BlobPropertyBag
 import kotlin.test.Test
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
@@ -189,6 +191,50 @@ class PlatformFileWebTest {
         )
     }
 
+    @OptIn(ExperimentalWasmJsInterop::class)
+    @Test
+    fun testPlatformFileFromBlob() = runTest {
+        val blob = Blob(
+            blobParts = listOf("Hello, World!".toJsString()).toJsArray(),
+            options = BlobPropertyBag(type = "text/plain"),
+        )
+
+        val file = PlatformFile(blob = blob, name = platformFile.name)
+
+        assertEquals(platformFile.name, file.name)
+        assertEquals(platformFile.extension, file.extension)
+        assertEquals(platformFile.nameWithoutExtension, file.nameWithoutExtension)
+        assertEquals(platformFile.size(), file.size())
+
+        assertEquals(
+            platformFile.readBytes().decodeToString(),
+            file.readBytes().decodeToString(),
+        )
+        assertEquals(
+            platformFile.readBytes().toList(),
+            file.readBytes().toList(),
+        )
+        assertEquals(platformFile.mimeType(), file.mimeType())
+        assertTrue(file.isRegularFile())
+        assertFalse(file.isDirectory())
+    }
+
+    @OptIn(ExperimentalWasmJsInterop::class)
+    @Test
+    fun testPlatformFileFromEmptyBlob() = runTest {
+        val blob = Blob(
+            blobParts = emptyList<JsAny?>().toJsArray(),
+            options = BlobPropertyBag(type = "application/octet-stream"),
+        )
+        val file = PlatformFile(blob = blob, name = "empty.bin")
+
+        assertEquals("empty.bin", file.name)
+        assertEquals(0L, file.size())
+        assertTrue(file.readBytes().isEmpty())
+        assertTrue(file.isRegularFile())
+        assertFalse(file.isDirectory())
+    }
+
     private fun PlatformFile.webFileWrapper(): WebFile.FileWrapper =
         assertIs<WebFile.FileWrapper>(webFile)
 }