feat(dependency-management): Improve dependency filtering for better output (#20)

This commit introduces several improvements to the dependency management system:

- Filters out unconnected dependencies to optimize output
- Automatically marks local types as required
- Marks imported types as required only if they are actually referenced by other types
- Automatically includes transitive dependencies when their parent types are referenced

The key changes are:

- Added `maincodeNodeIds` and `requiredNodeIds` sets to track main code and required nodes
- Updated `addLocalTypes` to mark local types as both main code and required
- Adjusted `collectFromImports` to only mark imported types as required if they are referenced
- Implemented filtering logic in `getNodesToPrint` to return only the required nodes

These changes ensure the dependency analysis produces a more optimized output, only including the necessary types and their transitive dependencies.

Author: DaxServer

docs/dependency-management.md

@@ -1,6 +1,6 @@
 # Dependency Management
 
-Graph-based dependency analysis for proper type processing order.
+Graph-based dependency analysis for proper type processing order with intelligent filtering of unconnected dependencies.
 
 ## Components
 
@@ -9,6 +9,7 @@ Graph-based dependency analysis for proper type processing order.
 Main orchestrator in `src/traverse/dependency-traversal.ts`:
 
 - Coordinates dependency collection
+- Filters out unconnected dependencies
 - Returns topologically sorted nodes
 
 ### FileGraph
@@ -28,11 +29,20 @@ Handles type-level dependencies in `src/traverse/node-graph.ts`:
 
 ## Process
 
-1. Collect local types from main file
-2. Process import chains recursively
-3. Extract type dependencies
-4. Build dependency graph
-5. Topological sort for processing order
+1. Collect local types from main file (automatically marked as required)
+2. Process import chains recursively (adds types to graph)
+3. Extract type dependencies (marks referenced types as required)
+4. Filter to only connected dependencies
+5. Build dependency graph
+6. Topological sort for processing order
+
+## Dependency Filtering
+
+The system now filters out unconnected dependencies to optimize output:
+
+- **Local types**: Always included (defined in main file)
+- **Imported types**: Only included if actually referenced by other types
+- **Transitive dependencies**: Automatically included when their parent types are referenced
 
 ## Circular Dependencies
 

docs/maincode-filtering.md

@@ -0,0 +1,115 @@
+# Maincode Filtering
+
+The code generator automatically filters the output to include only maincode nodes and their connected dependencies. This feature reduces the generated output by excluding imported types that are not actually used by the main code.
+
+## Overview
+
+The code generator includes only the following nodes in the output:
+
+1. **Maincode nodes**: Types defined in the main source file (not imported)
+2. **Connected dependencies**: Types that are directly or indirectly referenced by maincode nodes
+
+Imported types that are not referenced anywhere in the dependency chain are automatically filtered out.
+
+## Example
+
+Consider the following file structure:
+
+**external.ts**
+
+```typescript
+export type UsedType = {
+  value: string
+}
+
+export type UnusedType = {
+  unused: boolean
+}
+```
+
+**main.ts**
+
+```typescript
+import { UsedType, UnusedType } from './external'
+
+export interface MainInterface {
+  data: UsedType // UsedType is referenced and will be included
+}
+
+export type SimpleType = {
+  id: string
+}
+
+// UnusedType is imported but not referenced, so it will be filtered out
+```
+
+### Generated Output
+
+```typescript
+const result = generateCode({
+  filePath: './main.ts',
+})
+```
+
+**Output automatically excludes unconnected imports:**
+
+```typescript
+export const UsedType = Type.Object({
+  value: Type.String(),
+})
+
+export const MainInterface = Type.Object({
+  data: UsedType,
+})
+
+export const SimpleType = Type.Object({
+  id: Type.String(),
+})
+
+// UnusedType is not included because it's not connected to any maincode node
+```
+
+## Dependency Chain Handling
+
+The filtering algorithm correctly handles deep dependency chains. If a maincode node references a type that has its own dependencies, all dependencies in the chain are included:
+
+**level1.ts**
+
+```typescript
+export type Level1 = {
+  value: string
+}
+```
+
+**level2.ts**
+
+```typescript
+import { Level1 } from './level1'
+export type Level2 = {
+  level1: Level1
+}
+```
+
+**main.ts**
+
+```typescript
+import { Level2 } from './level2'
+
+export interface MainType {
+  data: Level2
+}
+```
+
+The output automatically includes `Level1`, `Level2`, and `MainType` because they form a complete dependency chain starting from the maincode node `MainType`.
+
+## Implementation Details
+
+The filtering algorithm:
+
+1. Identifies maincode nodes (nodes with `isImported: false`) and marks them as required
+2. Analyzes type references to identify which imported types are actually used
+3. Marks referenced types and their transitive dependencies as required
+4. Filters the final output to include only required nodes
+5. Returns the filtered nodes in topological order to maintain proper dependency ordering
+
+This approach ensures that only types that are part of a connected dependency graph starting from maincode nodes are included in the output.

docs/overview.md

@@ -48,4 +48,5 @@ export type User = Static<typeof User>
 - [handler-system.md](./handler-system.md) - Type conversion
 - [compiler-configuration.md](./compiler-configuration.md) - Compiler options and script targets
 - [dependency-management.md](./dependency-management.md) - Dependency analysis
+- [maincode-filtering.md](./maincode-filtering.md) - Filtering output to maincode and dependencies
 - [testing.md](./testing.md) - Testing

src/traverse/dependency-extractor.ts

@@ -0,0 +1,57 @@
+import { NodeGraph } from '@daxserver/validation-schema-codegen/traverse/node-graph'
+import { TypeReferenceExtractor } from '@daxserver/validation-schema-codegen/traverse/type-reference-extractor'
+import {
+  EnumDeclaration,
+  FunctionDeclaration,
+  InterfaceDeclaration,
+  Node,
+  TypeAliasDeclaration,
+} from 'ts-morph'
+
+export const extractDependencies = (nodeGraph: NodeGraph, requiredNodeIds: Set<string>): void => {
+  const processedNodes = new Set<string>()
+  const nodesToProcess = new Set(requiredNodeIds)
+  const typeReferenceExtractor = new TypeReferenceExtractor(nodeGraph)
+
+  // Process nodes iteratively until no new dependencies are found
+  while (nodesToProcess.size > 0) {
+    const currentNodeId = Array.from(nodesToProcess)[0]
+    if (!currentNodeId) break
+
+    nodesToProcess.delete(currentNodeId)
+
+    if (processedNodes.has(currentNodeId)) continue
+    processedNodes.add(currentNodeId)
+
+    const nodeData = nodeGraph.getNode(currentNodeId)
+    if (!nodeData) continue
+
+    let nodeToAnalyze: Node | undefined
+
+    if (nodeData.type === 'typeAlias') {
+      const typeAlias = nodeData.node as TypeAliasDeclaration
+      nodeToAnalyze = typeAlias.getTypeNode()
+    } else if (nodeData.type === 'interface') {
+      nodeToAnalyze = nodeData.node as InterfaceDeclaration
+    } else if (nodeData.type === 'enum') {
+      nodeToAnalyze = nodeData.node as EnumDeclaration
+    } else if (nodeData.type === 'function') {
+      nodeToAnalyze = nodeData.node as FunctionDeclaration
+    }
+
+    if (!nodeToAnalyze) continue
+
+    const typeReferences = typeReferenceExtractor.extractTypeReferences(nodeToAnalyze)
+
+    for (const referencedType of typeReferences) {
+      if (nodeGraph.hasNode(referencedType)) {
+        // Only add to required if not already processed
+        if (!requiredNodeIds.has(referencedType)) {
+          requiredNodeIds.add(referencedType)
+          nodesToProcess.add(referencedType)
+        }
+        nodeGraph.addDependency(referencedType, currentNodeId)
+      }
+    }
+  }
+}