Indexion Refactor

indexion refactor — Codebase Refactoring

Detect and eliminate duplication at three levels — textual, structural, and conceptual — using indexion's analysis commands, then verify SoT is enforced.

When to Use

• After adding a new abstraction (type, module, API layer)
• After introducing a new file format or I/O boundary
• When a fix required touching 3+ files for the same reason
• When a "guard" or "skip" was added to work around a structural problem
• When opendir, ENOENT, or similar filesystem errors appear from unexpected paths
• When extracting shared code across packages
• When cleaning up after a refactor (removing trivial wrapper functions)
• Periodic SoT health check on a codebase

Three Levels of Duplication

Textual duplication is easy to find and fix. Conceptual duplication is the hardest and most dangerous — it produces no copy-paste matches but means changing one concept requires updating every scattered implementation.

Workflow

Phase 1: Clear textual duplication (plan refactor)

Start with high-confidence matches and work down.

# Step 1: Find 90%+ duplicates (high confidence)
indexion plan refactor --threshold=0.9 \
  --include='*.mbt' --exclude='*_wbtest.mbt' \
  --exclude='*moon.pkg*' --exclude='*pkg.generated*' \
  cmd/indexion/

indexion plan refactor --threshold=0.9 \
  --include='*.mbt' --exclude='*_wbtest.mbt' \
  --exclude='*moon.pkg*' --exclude='*pkg.generated*' \
  src/

Read the output in three sections:

Same-file duplicates (functions within one file at 90%+) are the highest-value targets — easiest to fix, clearest wins. Example: get_global_data_dir and get_global_cache_dir share 95% structure, extracted into resolve_os_dir.

# Step 2: Use grep to trace references before consolidating
indexion grep "TypeIdent:TfidfEmbeddingProvider" src/
indexion grep --semantic=name:is_whitespace src/

# Step 3: Fix, then re-run to confirm duplicates are gone
indexion plan refactor --threshold=0.9 --include='*.mbt' ...

# Step 4: Lower threshold and iterate
indexion plan refactor --threshold=0.85 --include='*.mbt' ...

`plan refactor` options:

What remains after cleanup (stop signals):

• Platform stubs (native.mbt / stub.mbt) — intentional platform branching
• Type method similarity (to_string on different types) — different types, same pattern
• CLI command boilerplate (command() functions) — @argparse API pattern, not duplication
• Semantic-but-different functions (is_disqualifying_keyword vs is_skip_token) — different purpose

Phase 2: Extract cross-package shared code (plan solid)

After cleaning within each directory, find code that should be shared across packages.

# Find overlap between two packages
indexion plan solid --from=src/a,src/b

# Specify extraction target
indexion plan solid --from=src/a,src/b --to=src/common

# Use tree edit distance for precise function-level matching
indexion plan solid --from=src/a,src/b --strategy=apted

# Higher threshold for stricter matching
indexion plan solid --from=src/a,src/b --threshold=0.95

# Filter files
indexion plan solid --from=src/a,src/b --include='*.mbt' --exclude='*_test.mbt'

plan solid differs from plan refactor:

`plan solid` options:

Workflow:

1. Run plan refactor on each directory individually first to clean internal duplication
2. Run plan solid --from=dirA,dirB to find cross-directory extraction candidates
3. Extract shared code following the plan's recommendations
4. Use indexion grep "TypeIdent:SharedType" to verify all references are updated

Phase 3: Remove unnecessary wrappers (plan unwrap)

After consolidation, clean up trivial delegation functions that add indirection without value.

# Step 1: Quick check
indexion grep --semantic=proxy src/

# Step 2: Detailed report
indexion plan unwrap --include='*.mbt' --exclude='*_wbtest.mbt' \
  --exclude='*moon.pkg*' --exclude='*pkg.generated*' src/

# Step 3: Preview changes (safe — no files modified)
indexion plan unwrap --dry-run --include='*.mbt' --exclude='*_wbtest.mbt' \
  --exclude='*moon.pkg*' --exclude='*pkg.generated*' src/

# Step 4: Apply fixes
indexion plan unwrap --fix --include='*.mbt' --exclude='*_wbtest.mbt' \
  --exclude='*moon.pkg*' --exclude='*pkg.generated*' src/

# Step 5: Run tests
moon test --target native

What gets detected: Functions whose body is a single function call with all arguments forwarded as simple identifiers — no control flow, no transforms.

// Detected (default) — trivial delegation
fn matches_pattern(text : String, pat : String) -> Bool {
  @glob.glob_match(text, pat)
}

// Excluded by default (use --all to include)
fn length(self : MyList) -> Int {
  self.items.length()    // self-delegation (encapsulation)
}
fn emit(value : String) -> Action {
  Emit(value)            // bare constructor
}

`plan unwrap` modes:

`plan unwrap` options: