Claude-skill-registry ln-723-mockdata-migrator

Migrates mock data from Drizzle ORM schemas to C# MockData classes

install

source · Clone the upstream repo

git clone https://github.com/majiayu000/claude-skill-registry

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/majiayu000/claude-skill-registry "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/data/levn-ln-723-mockdata-migrator" ~/.claude/skills/majiayu000-claude-skill-registry-ln-723-mockdata-migrator && rm -rf "$T"

manifest: skills/data/levn-ln-723-mockdata-migrator/SKILL.md

ln-723-mockdata-migrator

Type: L3 Worker Category: 7XX Project Bootstrap Parent: ln-720-structure-migrator

Migrates mock data from ORM schemas to .NET MockData classes with realistic sample data.

Purpose & Scope

Aspect	Description
Input	ORM schema files (Drizzle, Prisma, TypeORM)
Output	C# MockData static classes
Primary ORM	Drizzle (others supported)

Scope boundaries:

Parses ORM schema definitions
Generates C# entities and MockData classes
Creates realistic sample data
Does not generate database migrations or EF Core configs

Workflow

Phase	Name	Actions	Output
1	Parse Schema	Read ORM file, extract table definitions	Entity model
2	Map Types	Apply type mapping rules, detect nullable	C# type definitions
3	Generate MockData	Create static class, generate sample data	MockData.cs files
4	Verify	Compile check, relationship validation	Valid C# code

Phase 1: Parse Schema

Extract entity definitions from ORM schema.

Step	Action	Reference
1.1	Locate schema file(s)	—
1.2	Identify ORM type (Drizzle/Prisma/TypeORM)	Detect by syntax
1.3	Extract table definitions	`drizzle_patterns.md`
1.4	Extract column definitions	`drizzle_patterns.md`
1.5	Identify constraints (PK, FK, nullable)	`drizzle_patterns.md`
1.6	Extract enum definitions	`drizzle_patterns.md`

Output: Entity model with columns, types, and constraints.

Phase 2: Map Types

Convert ORM types to C# types.

Step	Action	Reference
2.1	Map column types to C#	`type_mapping.md`
2.2	Determine nullable status	`type_mapping.md`
2.3	Identify primary keys	`type_mapping.md`
2.4	Map foreign keys	`relationship_mapping.md`
2.5	Transform names (snake_case → PascalCase)	`drizzle_patterns.md`

Type mapping summary:

ORM Type	C# Type	Nullable Rule
uuid	Guid	No (PK), Depends (FK)
varchar	string	Check .notNull()
integer	int	No
boolean	bool	No
timestamp	DateTime	Depends

Phase 3: Generate MockData

Create C# MockData class with sample data.

Step	Action	Reference
3.1	Create MockData class	`data_generation.md`
3.2	Generate GUIDs for entities	`data_generation.md`
3.3	Generate sample data per field	`data_generation.md`
3.4	Ensure FK relationships valid	`relationship_mapping.md`
3.5	Create accessor methods	`data_generation.md`

Generation order by dependency:

Order	Entity Type	Generate After
1	Root entities (no FK)	First
2	First-level children	Parents exist
3	Second-level children	Grandparents exist
N	Deepest children	All ancestors exist

Phase 4: Verify

Validate generated code.

Check	Method	Expected
Syntax valid	Compile check	No errors
FKs valid	Cross-reference	All FKs point to existing IDs
Types correct	Type analysis	Proper C# types
Names follow convention	Pattern check	PascalCase

Supported ORM Detection

ORM Detection Pattern

Drizzle

pgTable()

mysqlTable()

sqliteTable()

Prisma

model X {

syntax

TypeORM

@Entity()

@Column()

decorators

Entity Transformation Rules

Source	Target	Transformation
Table name (plural, snake)	Class name (singular, Pascal)	`user_profiles` → `UserProfile`
Column name (snake)	Property name (Pascal)	`created_at` → `CreatedAt`
Enum name	Enum type (Pascal)	`status_enum` → `StatusEnum`
FK column	Navigation property	`user_id` → `UserId`

MockData Class Structure

Component	Purpose
Private static list	Holds immutable mock data
GetAll() method	Returns full list as IEnumerable
GetById(Guid id)	Finds single entity by ID
GetBy{FK}Id(Guid id)	Filters by foreign key

Sample Data Guidelines

Field Type	Sample Count	Distribution
Root entities	3-5 items	Varied status/priority
Child entities	5-10 items	Distributed across parents
Leaf entities	10-20 items	Realistic variety

Critical Rules

Single Responsibility: Generate only MockData, no database code
Idempotent: Can re-run to regenerate
Valid Relationships: All FKs must reference existing parent IDs
Realistic Data: Use domain-appropriate values, not random strings
Generation Order: Parents before children
Consistent GUIDs: Use fixed GUIDs for reproducibility

Definition of Done

Schema file parsed successfully
All tables/entities extracted
Type mappings applied correctly
MockData class generated per feature/entity group
Sample data includes 5-10 items per entity
Foreign keys reference valid parent IDs
Accessor methods generated (GetAll, GetById)
Code compiles without errors

Risk Mitigation

Risk	Detection	Mitigation
Parse failure	Exception during parse	Support multiple schema formats
Invalid type mapping	Unknown ORM type	Log warning, use string as fallback
FK mismatch	FK references non-existent ID	Generate parents first, validate after
Name collision	Duplicate class names	Prefix with feature name
Circular references	Self-referencing with cycles	Limit depth, validate graph

Reference Files

File	Purpose
`references/type_mapping.md`	ORM to C# type conversion rules
`references/drizzle_patterns.md`	Drizzle schema parsing patterns
`references/data_generation.md`	Realistic sample data patterns
`references/relationship_mapping.md`	FK handling and generation order

Version: 2.0.0 Last Updated: 2026-01-10