migrate-custom-code

Migrate Custom Code

ATC-driven S/4HANA custom code migration assistant with automated fix proposals.

This skill replicates SAP Joule's "Custom Code Migration" capability by combining ARC-1 (SAP system access) with mcp-sap-docs (documentation & best practices). It runs ATC readiness checks, groups and explains findings, and generates replacement code following modern ABAP patterns.

Smart Defaults (apply silently, do NOT ask)

Setting	Default	Rationale
Object type	Auto-detect via SAPSearch	Don't make user look up the type
ATC variant	System default	Omitting variant makes ARC-1 resolve and send systemCheckVariant
Scope	fix (explain + fix proposals)	Most actionable output
Priority filter	All priorities (start with Priority 1 errors)	Don't miss anything, but fix most critical first

Input

The user provides an object or package to check (e.g., ZCL_SALES_HANDLER, Z_REPORT_POSTING, ZSALES_PKG).

Only the object name is required. If the user provides just an object name, auto-detect the type and proceed with the default variant and fix scope.

Optionally, the user may specify:

• Object type (default: auto-detect via SAPSearch)
• Target release variant (e.g., S4HANA_2023, S4HANA_READINESS; default: system default)
• Scope — explain (findings only) or fix (explain + fix proposals; default: fix)

Step 1: Run ATC Readiness Check

ATC gotchas (verified live on S/4HANA 2023):

• ATC skips $TMP / local objects. A check run against a $TMP object resolves to an empty object set and returns zero findings — this is not "clean code", it's "not checked". Run ATC against objects in a transportable package. If the user points you at $TMP code, say so and ask them to assign it to a transportable package first.
• The check variant must exist on the system. ABAP_CLOUD_READINESS is the standard name on SAP BTP ABAP / S/4HANA Cloud, but on-premise systems often ship S4HANA_READINESS_<release> (e.g. S4HANA_READINESS_2023) or SAP_CLOUD_PLATFORM_DEFAULT instead. If the named variant is absent ARC-1 rejects the call (SAP would silently run DEFAULT) — list the real names with SAPDiagnose(action="atc_variants"), or omit variant to bind the system's configured default.