fix(JsBridge): meaningful error when module/method routing fails (#25)

[jim-daf]

Meaningful error when module or method routing fails (refs #25)

Resolves #25

Why "JBArgument Parse error" is misleading

In JsBridgeImpl.onCallJsPrompt the error path is:

JBArgumentParser argumentParser = JBArgumentParser.parse(methodArgs);
if (argumentParser.isSuccess() && ... ) {
    JsModule findModule = getModule(argumentParser.getModule());
    if (findModule != null) {
        HashMap<String, JsMethod> methodHashMap = exposedMethods.get(findModule);
        if (methodHashMap != null && ... && methodHashMap.containsKey(...)) {
            ...
            return true;
        }
    }
    setJsPromptResult(result, false, "JBArgument Parse error");
    return true;
}

The JSON itself parsed fine (isSuccess() is true). The error fires when the named module or method is not registered on the Java side. Reporting that as "JBArgument Parse error" sends the developer looking at their JS payload, not at their Java module list. Issue #25 is exactly this misdirection.

The fix

Split the failure modes:

if (findModule == null) {
    String msg = "Module not found: " + argumentParser.getModule();
    JBLog.e(msg, null);
    setJsPromptResult(result, false, msg);
    return true;
}
HashMap<String, JsMethod> methodHashMap = exposedMethods.get(findModule);
if (methodHashMap == null || methodHashMap.isEmpty()
        || !methodHashMap.containsKey(argumentParser.getMethod())) {
    String msg = "Method not found: " + argumentParser.getModule()
            + "." + argumentParser.getMethod();
    JBLog.e(msg, null);
    setJsPromptResult(result, false, msg);
    return true;
}

The fail callback on the JS side now receives "Module not found: networkInfo" or "Method not found: <module>.networkInfo" instead of the generic string, which is enough to debug the original report (the user was seeing intermittent calls fail under exactly this code path).

Parser robustness

Also trim the incoming jsonString before the startsWith("{") check so a stray leading whitespace or BOM coming through onJsPrompt does not look like a malformed payload:

String trimmed = jsonString == null ? null : jsonString.trim();
if(TextUtils.isEmpty(trimmed) || (!trimmed.startsWith("{") &&
        !trimmed.startsWith("["))) {
    parser.setThrowable(new JSONException("Argument error: " + jsonString));
    return parser;
}

Files changed

• jsbridge/src/main/java/com/apkfuns/jsbridge/JBArgumentParser.java
• jsbridge/src/main/java/com/apkfuns/jsbridge/JsBridgeImpl.java

[Copilot]

Pull request overview

Improves JsBridge error reporting so JS callers get actionable messages when native module/method routing fails, and makes argument parsing more tolerant of leading whitespace.

Changes:

• Return specific "Module not found: ..." / "Method not found: ..." errors instead of the misleading generic parse error.
• Trim incoming JSON before validating/parsing to avoid failures due to leading whitespace.
• Adjust logging to align with the new failure modes.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
jsbridge/src/main/java/com/apkfuns/jsbridge/JsBridgeImpl.java	Splits routing failure paths to report missing module/method explicitly.
jsbridge/src/main/java/com/apkfuns/jsbridge/JBArgumentParser.java	Trims JSON input before parsing to improve robustness against leading whitespace.

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[Copilot]

The if (true) block is unconditional and appears to be leftover scaffolding from the previous nested if (findModule != null) logic. It adds an unnecessary indentation level and makes the control flow harder to follow. Remove the if (true) and unindent the enclosed code.

[Copilot]

The comment says trimming handles a leading BOM, but String.trim() does not remove the UTF-8 BOM character (\uFEFF). Either strip a BOM explicitly (and document it), or remove the BOM claim from the comment to avoid misleading future maintainers.

Suggested change

	// Issue #25: trim before the startsWith check so a leading
	// whitespace or BOM coming through the prompt channel does
	// not look like a malformed payload.
	String trimmed = jsonString == null ? null : jsonString.trim();
	// Issue #25: strip a leading BOM explicitly, then trim before
	// the startsWith check so leading whitespace or a BOM coming
	// through the prompt channel does not look like a malformed payload.
	String trimmed = jsonString;
	if (trimmed != null && trimmed.startsWith("\uFEFF")) {
	trimmed = trimmed.substring(1);
	}
	trimmed = trimmed == null ? null : trimmed.trim();

[Copilot]

The startsWith("[") check suggests JSON arrays are supported, but the code always parses with new JSONObject(...), which will throw for array payloads. Either remove the [ acceptance here, or add proper JSONArray handling so the pre-check matches what the parser can actually consume.