figma-migration-deep-dive

# Figma Migration Deep Dive

## Overview
Automate migration of design data between Figma files, from other tools to Figma, or from Figma styles to the Variables API. Covers inventory, extraction, transformation, and validation.

## Prerequisites
- Source and destination Figma file keys
- `FIGMA_PAT` with `file_content:read` and `file_variables:write` (Enterprise) scopes
- Understanding of source file structure

## Instructions

### Step 1: Inventory Source File
```typescript
const PAT = process.env.FIGMA_PAT!;

async function inventoryFile(fileKey: string) {
  const res = await fetch(
    `https://api.figma.com/v1/files/${fileKey}`,
    { headers: { 'X-Figma-Token': PAT } }
  );
  const file = await res.json();

  const inventory = {
    name: file.name,
    pages: file.document.children.map((p: any) => p.name),
    componentCount: Object.keys(file.components).length,
    styleCount: Object.keys(file.styles).length,
    styles: {
      fills: Object.values(file.styles).filter((s: any) => s.style_type === 'FILL').length,
      text: Object.values(file.styles).filter((s: any) => s.style_type === 'TEXT').length,
      effects: Object.values(file.styles).filter((s: any) => s.style_type === 'EFFECT').length,
      grids: Object.values(file.styles).filter((s: any) => s.style_type === 'GRID').length,
    },
  };

  // Count total nodes
  let nodeCount = 0;
  function countNodes(node: any) {
    nodeCount++;
    if (node.children) node.children.forEach(countNodes);
  }
  countNodes(file.document);
  (inventory as any).totalNodes = nodeCount;

  return inventory;
}

// Usage
const inv = await inventoryFile(process.env.FIGMA_FILE_KEY!);
console.log(`File: ${inv.name}`);
console.log(`Pages: ${inv.pages.join(', ')}`);
console.log(`Components: ${inv.componentCount}, Styles: ${inv.styleCount}`);
console.log(`Total nodes: ${(inv as any).totalNodes}`);
```

### Step 2: Extract Styles from Source
```typescript
async function extractAllStyles(fileKey: string) {
  const file = await fetch(
    `https://api.figma.com/v1/files/${fileKey}`,
    { headers: { 'X-Figma-Token': PAT } }
  ).then(r => r.json());

  const styleNodeIds = Object.keys(file.styles);
  const nodesRes = await fetch(
    `https://api.figma.com/v1/files/${fileKey}/nodes?ids=${styleNodeIds.join(',')}`,
    { headers: { 'X-Figma-Token': PAT } }
  ).then(r => r.json());

  const extracted = [];
  for (const [nodeId, styleMeta] of Object.entries(file.styles) as any[]) {
    const node = nodesRes.nodes[nodeId]?.document;
    if (!node) continue;

    extracted.push({
      name: styleMeta.name,
      type: styleMeta.style_type,
      nodeId,
      data: {
        fills: node.fills,
        strokes: node.strokes,
        effects: node.effects,
        style: node.style,       // typography
        characters: node.characters,
      },
    });
  }

  return extracted;
}
```

### Step 3: Transform and Map to Target
```typescript
// Map extracted styles to design tokens JSON
interface MigrationToken {
  name: string;
  category: 'color' | 'typography' | 'effect';
  source: { file: string; nodeId: string };
  value: any;
}

function transformStyles(styles: any[], sourceFileKey: string): MigrationToken[] {
  return styles.map(style => {
    switch (style.type) {
      case 'FILL':
        const fill = style.data.fills?.[0];
        return {
          name: style.name,
          category: 'color' as const,
          source: { file: sourceFileKey, nodeId: style.nodeId },
          value: fill?.color
            ? {
                r: Math.round(fill.color.r * 255),
                g: Math.round(fill.color.g * 255),
                b: Math.round(fill.color.b * 255),
                a: fill.color.a ?? 1,
              }
            : null,
        };
      case 'TEXT':
        return {
          name: style.name,
          category: 'typography' as const,
          source: { file: sourceFileKey, nodeId: style.nodeId },
          value: style.data.style
            ? {
                fontFamily: style.data.style.fontFamily,
                fontSize: style.data.style.fontSize,
                fontWeight: style.data.style.fontWeight,
                lineHeight: style.data.style.lineHeightPx,
              }
            : null,
        };
      default:
        return {
          name: style.name,
          category: 'effect' as const,
          source: { file: sourceFileKey, nodeId: style.nodeId },
          value: style.data.effects,
        };
    }
  }).filter(t => t.value !== null);
}
```

### Step 4: Write to Target (Variables API)
```typescript
// Enterprise only: create variables in the target file
async function migrateToVariables(
  targetFileKey: string,
  tokens: MigrationToken[]
) {
  const colorTokens = tokens.filter(t => t.category === 'color');

  // Create variable collection and variables
  const payload = {
    variableCollections: [{
      action: 'CREATE' as const,
      id: 'temp_collection_1',
      name: 'Migrated Colors',
    }],
    variables: colorTokens.map((token, i) => ({
      action: 'CREATE' as const,
      id: `temp_var_${i}`,
      name: token.name.replace(/\//g, '/'), // preserve Figma group paths
      variableCollectionId: 'temp_collection_1',
      resolvedType: 'COLOR' as const,
      codeSyntax: { WEB: `--${token.name.toLowerCase().replace(/[\s/]+/g, '-')}` },
    })),
    variableModeValues: colorTokens.map((token, i) => ({
      variableId: `temp_var_${i}`,
      modeId: '', // Will use default mode
      value: {
        r: token.value.r / 255,
        g: token.value.g / 255,
        b: token.value.b / 255,
        a: token.value.a,
      },
    })),
  };

  const res = await fetch(
    `https://api.figma.com/v1/files/${targetFileKey}/variables`,
    {
      method: 'POST',
      headers: {
        'X-Figma-Token': PAT,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(payload),
    }
  );

  if (!res.ok) throw new Error(`Variable creation failed: ${res.status} ${await res.text()}`);
  return res.json();
}
```

### Step 5: Validation
```typescript
async function validateMigration(
  sourceFileKey: string,
  targetFileKey: string
): Promise<{ passed: boolean; issues: string[] }> {
  const sourceStyles = await extractAllStyles(sourceFileKey);
  const targetVars = await fetch(
    `https://api.figma.com/v1/files/${targetFileKey}/variables/local`,
    { headers: { 'X-Figma-Token': PAT } }
  ).then(r => r.json());

  const issues: string[] = [];
  const targetNames = new Set(
    Object.values(targetVars.meta.variables).map((v: any) => v.name)
  );

  for (const style of sourceStyles) {
    if (style.type === 'FILL' && !targetNames.has(style.name)) {
      issues.push(`Missing in target: ${style.name}`);
    }
  }

  return { passed: issues.length === 0, issues };
}
```

## Output
- Source file inventoried (components, styles, nodes)
- Styles extracted and transformed to tokens
- Tokens written to target file via Variables API
- Migration validated with comparison report

## Error Handling
| Error | Cause | Solution |
|-------|-------|----------|
| 403 on Variables POST | Not Enterprise | Use JSON export instead of Variables API |
| Duplicate variable names | Name collision in target | Add prefix/suffix to migrated names |
| Missing node data | Node deleted between fetch and read | Re-fetch with error handling |
| Large file timeout | File >100MB | Use `/nodes` endpoint for specific pages |

## Resources
- [Figma Variables API](https://developers.figma.com/docs/rest-api/variables-endpoints/)
- [Figma File Endpoints](https://developers.figma.com/docs/rest-api/file-endpoints/)
- [Design Tokens Format](https://design-tokens.github.io/community-group/format/)

## Next Steps
For advanced troubleshooting, see `figma-advanced-troubleshooting`.