{"passport":{"unfragile":{"@version":"1.0","version":"2026-05","artifact":{"id":"github-dave--jennifer","slug":"dave--jennifer","name":"jennifer","type":"repo","url":"https://github.com/dave/jennifer","page_url":"https://unfragile.ai/dave--jennifer","categories":["frameworks-sdks"],"tags":["code-generation","code-generator","go","golang"],"pricing":{"model":"open_source","free":true,"starting_price":null},"status":"active","verified":false},"capabilities":[{"id":"github-dave--jennifer__cap_0","uri":"capability://code.generation.editing.fluent.interface.based.go.code.construction.via.method.chaining","name":"fluent-interface-based go code construction via method chaining","description":"Jennifer provides a fluent API where methods return the receiver (Statement or Group) to enable natural method chaining that mirrors Go syntax structure. This approach eliminates string concatenation and templating by composing immutable code elements through a chain of method calls like f.Func().Id(\"main\").Params().Block(...), where each method adds tokens to an internal sequence and returns self for continued chaining.","intents":["Build Go code programmatically without writing raw strings or templates","Chain method calls to construct code that reads like the target Go syntax","Maintain type safety and syntactic correctness during code generation"],"best_for":["Go developers building code generators, scaffolding tools, or metaprogramming frameworks","Teams generating boilerplate code from specifications or schemas"],"limitations":["Fluent chains can become deeply nested for complex code structures, reducing readability","No IDE autocomplete hints for dynamic method chains in some editors","Method chaining overhead adds ~5-10% performance cost vs direct token manipulation"],"requires":["Go 1.11 or later","Import github.com/dave/jennifer/jen package"],"input_types":["method calls with string identifiers, literals, and code elements"],"output_types":["Go source code as strings or written to io.Writer"],"categories":["code-generation-editing","api-design"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_1","uri":"capability://code.generation.editing.automatic.import.resolution.and.management.with.conflict.detection","name":"automatic import resolution and management with conflict detection","description":"Jennifer automatically tracks package imports when Qual() is used to reference qualified identifiers (e.g., Qual(\"fmt\", \"Println\")). The File type maintains an import registry that deduplicates imports, detects naming conflicts, applies aliases when needed, and only renders imports that are actually used in the generated code. This eliminates manual import management and prevents unused import errors.","intents":["Automatically add imports for qualified package references without manual tracking","Resolve naming conflicts when multiple packages export identifiers with the same name","Ensure generated code has clean imports with no unused declarations"],"best_for":["Code generators that reference multiple external packages","Tools generating code with complex dependency graphs","Developers avoiding manual import statement management"],"limitations":["Cannot detect imports needed for type assertions or interface satisfaction that aren't explicitly referenced via Qual()","Alias resolution is automatic but may produce unexpected names if not carefully managed","No support for import grouping or custom import ordering beyond standard Go conventions"],"requires":["File type instance created with NewFile(packageName)","Use of Qual(importPath, identifier) for qualified references"],"input_types":["qualified identifier references via Qual() method"],"output_types":["import block in rendered Go source with automatic deduplication and alias management"],"categories":["code-generation-editing","automation-workflow"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_10","uri":"capability://code.generation.editing.comment.and.documentation.generation.with.proper.formatting","name":"comment and documentation generation with proper formatting","description":"Jennifer provides Comment() method for generating single-line comments and Comment() with multi-line support for block comments. Comments are rendered with proper // or /* */ syntax and indentation matching surrounding code. Documentation comments (starting with //) are automatically formatted to match Go conventions, enabling generation of documented code with proper comment placement.","intents":["Generate single-line comments for code clarity","Create block comments for documentation","Add documentation comments to functions and types"],"best_for":["Generating self-documenting code","Creating API documentation through code generation","Building code generators that produce commented code"],"limitations":["No built-in support for godoc-style comment formatting","Comment content is not validated; invalid comment syntax is not detected","No automatic comment wrapping for long lines"],"requires":["Comment text content"],"input_types":["comment text strings"],"output_types":["Go comments with proper syntax and indentation"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_11","uri":"capability://code.generation.editing.identifier.and.qualified.reference.generation.with.package.resolution","name":"identifier and qualified reference generation with package resolution","description":"Jennifer provides Id() for local identifiers, Qual() for qualified package references, and Dot() for member access. Id() generates simple identifiers like variable or function names, Qual(importPath, identifier) generates qualified references that trigger automatic import management, and Dot() chains member access like obj.Field. These methods form the foundation for building expressions that reference external packages, local variables, and nested members with automatic import tracking.","intents":["Generate local variable and function references","Create qualified package references with automatic imports","Build member access expressions (dot notation)"],"best_for":["Generating code that references external packages","Building expressions with member access","Creating code with complex identifier chains"],"limitations":["Qual() requires explicit import path; no automatic path resolution from package names","Dot() chains are linear; no support for method calls in chains without explicit Call()","No validation that identifiers are valid Go identifiers"],"requires":["Valid Go identifier names","Correct import paths for Qual() references"],"input_types":["identifier names, import paths, member names"],"output_types":["Go identifiers and qualified references"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_12","uri":"capability://code.generation.editing.literal.value.generation.with.type.specific.formatting","name":"literal value generation with type-specific formatting","description":"Jennifer provides Lit() for generic literals, LitRune() for rune literals, LitByte() for byte literals, and LitString() for string literals with proper escaping. Each method handles type-specific formatting: Lit() uses Go's %#v format for automatic type inference, LitRune() wraps values in single quotes, LitByte() produces byte literals, and LitString() handles escape sequences. These methods ensure literals are rendered with correct Go syntax and proper type representation.","intents":["Generate literal values with proper Go syntax","Create string literals with automatic escape handling","Generate rune and byte literals with correct formatting"],"best_for":["Generating code with hardcoded values","Creating test data or configuration literals","Building code generators that embed constant values"],"limitations":["Lit() uses %#v format which may not match all desired literal representations","No support for complex literal types like maps or slices in single Lit() call","String escape handling is automatic but may not match all edge cases"],"requires":["Literal values compatible with Go types"],"input_types":["Go values (strings, numbers, runes, bytes)"],"output_types":["Go literal expressions with proper syntax"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_13","uri":"capability://code.generation.editing.operator.expression.generation.with.proper.syntax","name":"operator expression generation with proper syntax","description":"Jennifer provides Op() method for generating operators in expressions, enabling construction of arithmetic, logical, comparison, and assignment operators. Op() takes an operator string and appends it to the Statement token sequence, allowing chaining with operands to build complete expressions. This enables programmatic construction of expressions like a + b, x == y, or ptr->field with proper operator syntax.","intents":["Generate arithmetic and logical expressions","Create comparison and assignment operations","Build complex expressions with multiple operators"],"best_for":["Generating mathematical or logical expressions","Creating conditional expressions","Building code with operator-heavy logic"],"limitations":["No built-in operator precedence handling; developer must structure calls correctly","No validation that operators are valid Go operators","Complex expressions with multiple operators can become difficult to read"],"requires":["Valid Go operator strings","Proper operand ordering for operator semantics"],"input_types":["operator strings"],"output_types":["Go operator expressions"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_14","uri":"capability://code.generation.editing.function.call.generation.with.arguments.and.method.chaining","name":"function call generation with arguments and method chaining","description":"Jennifer provides Call() method for generating function calls with arguments. Call() creates a Call group that renders with parentheses and comma-separated arguments, enabling construction of expressions like fmt.Println(\"hello\") or obj.Method(arg1, arg2). Arguments are specified through method chaining on the Call group, and the entire call expression can be chained with other methods to build complex call chains.","intents":["Generate function calls with arguments","Create method calls on objects","Build chained function calls"],"best_for":["Generating code that invokes functions or methods","Creating API calls or library usage code","Building code with complex call chains"],"limitations":["No built-in support for named arguments","Variadic arguments must be specified individually","No validation that function signatures match argument counts"],"requires":["Function or method reference","Argument expressions"],"input_types":["function/method reference, argument expressions"],"output_types":["Go function call expressions"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_15","uri":"capability://code.generation.editing.custom.formatting.and.rendering.control.via.render.method","name":"custom formatting and rendering control via render method","description":"Jennifer's Code interface exposes a render(io.Writer, *File) method that enables custom formatting and rendering logic. Developers can implement custom Code types with specialized render() implementations to produce non-standard formatting, conditional rendering based on File context, or integration with external formatting tools. The File parameter provides access to import registry and formatting state, enabling context-aware rendering decisions.","intents":["Implement custom code element types with specialized rendering","Apply custom formatting rules to generated code","Integrate external formatting tools or conventions"],"best_for":["Advanced code generators with custom formatting requirements","Teams building domain-specific code generation frameworks","Developers needing non-standard Go code output"],"limitations":["Requires understanding of io.Writer and Go's rendering patterns","Custom render implementations are not validated by Jennifer","No built-in hooks for pre/post-rendering processing"],"requires":["Implementation of Code interface with render(io.Writer, *File) error method","Understanding of io.Writer and formatting patterns"],"input_types":["custom Code type implementations"],"output_types":["custom formatted output via io.Writer"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_2","uri":"capability://code.generation.editing.type.safe.code.element.composition.via.code.interface","name":"type-safe code element composition via code interface","description":"Jennifer defines a Code interface that all code elements (Statement, Group, literals, identifiers) must implement with render(io.Writer, *File) methods. This interface-based architecture enables composable code construction where any Code-implementing type can be nested within another, providing compile-time type safety and ensuring all elements can be rendered correctly. The File parameter in render() provides context for import resolution and formatting decisions.","intents":["Compose code elements safely knowing they implement the Code interface","Nest code structures arbitrarily deep while maintaining type correctness","Ensure all generated code elements can be rendered without runtime errors"],"best_for":["Complex code generators requiring deep nesting of code structures","Teams building domain-specific code generation frameworks on top of Jennifer","Developers wanting compile-time guarantees about code element validity"],"limitations":["Interface-based design adds indirection overhead (~2-3% performance cost per render call)","Custom Code implementations require implementing both render() and potentially other methods","No built-in validation that composed code elements form syntactically valid Go"],"requires":["Understanding of Go interfaces and method receivers","Implementation of render(io.Writer, *File) error method for custom Code types"],"input_types":["any type implementing the Code interface"],"output_types":["rendered Go source code via io.Writer"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_3","uri":"capability://code.generation.editing.statement.based.token.sequencing.with.operator.and.literal.support","name":"statement-based token sequencing with operator and literal support","description":"Statement is the primary building block in Jennifer, internally maintaining a sequence of tokens that represent Go code. Statements provide methods for adding identifiers (Id(), Qual(), Dot()), literals (Lit(), LitRune(), LitByte()), operators (Op()), and control structures (If(), For(), Switch(), Return()). Each method appends tokens to the sequence and returns the Statement for chaining, enabling progressive construction of complex expressions and statements.","intents":["Build expressions and statements by sequencing identifiers, literals, and operators","Construct control flow structures (if, for, switch) with proper nesting","Create function calls, array indexing, and other Go language constructs"],"best_for":["Generating expressions, assignments, and control flow statements","Building function bodies and method implementations","Creating complex nested expressions with proper operator precedence"],"limitations":["Token sequencing is linear; no built-in operator precedence handling (developer must structure calls correctly)","No validation that token sequences form valid Go syntax until render time","Complex nested expressions can become difficult to read despite fluent chaining"],"requires":["Understanding of Go syntax and operator precedence","Proper method call ordering to match desired Go code structure"],"input_types":["method calls with identifiers, literals, operators, and control structures"],"output_types":["Go expressions and statements as rendered strings"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_4","uri":"capability://code.generation.editing.group.based.code.organization.with.context.aware.rendering","name":"group-based code organization with context-aware rendering","description":"Group is a container for organizing collections of code elements with different rendering semantics depending on context. Jennifer provides specialized group types: Block (renders with braces and newlines for function bodies), Values (renders with braces and commas for slice/struct literals), Call (renders with parentheses and commas for function calls), Params (renders with parentheses and commas for function parameters), and Index (renders with brackets and colons for array indexing). Each group type automatically applies appropriate separators and delimiters based on its semantic purpose.","intents":["Organize multiple code elements with appropriate delimiters and separators","Render function bodies with braces and newlines","Create function calls, parameter lists, and array indexing with proper syntax"],"best_for":["Generating function bodies, parameter lists, and collection literals","Building complex nested structures with multiple code elements","Creating readable multi-line code with proper indentation"],"limitations":["Group types are fixed; no custom separator/delimiter combinations","Nested groups can produce deeply indented code that may exceed line length limits","No built-in support for custom formatting rules or conditional rendering within groups"],"requires":["Understanding of group type semantics (Block vs Values vs Call, etc.)","Proper nesting of groups to match Go syntax structure"],"input_types":["Code elements (Statements, other Groups, literals)"],"output_types":["rendered Go code with appropriate delimiters and separators"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_5","uri":"capability://code.generation.editing.file.level.code.generation.with.package.and.import.management","name":"file-level code generation with package and import management","description":"File represents a complete Go source file and manages package declarations, import statements, and top-level code elements. File tracks all Qual() references through its internal import registry, renders the package declaration, generates the import block with automatic deduplication and alias resolution, and then renders all code elements in order. The File type provides methods to add functions, types, variables, and constants, and can render to an io.Writer or return a formatted string.","intents":["Generate complete Go source files with proper package and import declarations","Manage top-level code elements (functions, types, variables) in a single file","Render entire files with automatic formatting and import management"],"best_for":["Code generators producing complete Go files","Tools scaffolding packages or modules","Developers generating multiple related files programmatically"],"limitations":["File represents a single package; multi-package generation requires multiple File instances","No built-in support for file-level comments or build tags","Import ordering follows Go conventions but cannot be customized"],"requires":["Package name provided to NewFile(packageName)","io.Writer or string output target for rendering"],"input_types":["code elements (functions, types, variables, constants)"],"output_types":["complete Go source file as string or written to io.Writer"],"categories":["code-generation-editing","automation-workflow"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_6","uri":"capability://code.generation.editing.function.and.method.declaration.with.receiver.parameters.and.return.types","name":"function and method declaration with receiver, parameters, and return types","description":"Jennifer provides methods to generate function and method declarations with full support for receivers, parameters, return types, and function bodies. The Func() method creates a function declaration, Receiver() adds a receiver for methods, Params() defines parameters with types, Returns() specifies return types, and Block() contains the function body. Each method returns the Statement for chaining, enabling natural construction of function signatures followed by bodies.","intents":["Generate function declarations with parameters and return types","Create method declarations with receivers","Build function bodies with control flow and statements"],"best_for":["Generating API implementations or interface implementations","Creating boilerplate functions and methods","Building code generators that produce function-heavy code"],"limitations":["No built-in support for variadic parameters or named return types in a single call","Function body must be constructed separately; no inline body syntax","No support for generic function parameters (Go 1.18+) in current Jennifer versions"],"requires":["Understanding of Go function and method syntax","Proper parameter and return type specification"],"input_types":["function name, receiver type, parameter names/types, return types"],"output_types":["Go function or method declaration with body"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_7","uri":"capability://code.generation.editing.control.flow.structure.generation.if.for.switch.return","name":"control flow structure generation (if, for, switch, return)","description":"Jennifer provides methods to generate control flow structures: If() for conditional blocks, For() for loops, Switch() for switch statements, and Return() for return statements. Each method creates a Statement that can be chained with conditions, loop ranges, switch cases, and return values. Control flow structures can contain nested Blocks or other statements, enabling complex nested control flow generation with proper indentation and formatting.","intents":["Generate if/else conditional blocks with conditions","Create for loops with range, condition, or traditional syntax","Build switch statements with multiple cases","Generate return statements with values"],"best_for":["Generating function bodies with complex control flow","Creating boilerplate code with conditional logic","Building code generators for state machines or decision trees"],"limitations":["No built-in support for defer or panic statements","Switch case handling requires manual case construction; no automatic case generation","Nested control flow can become deeply indented and difficult to read"],"requires":["Understanding of Go control flow syntax","Proper nesting of control structures within Blocks"],"input_types":["conditions, loop ranges, switch expressions, return values"],"output_types":["Go control flow statements with proper indentation"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_8","uri":"capability://code.generation.editing.struct.and.interface.type.declaration.with.fields.and.methods","name":"struct and interface type declaration with fields and methods","description":"Jennifer enables generation of struct and interface type declarations through Type() method combined with Struct() or Interface() for the type body. Struct fields are added with Field() specifying name, type, and optional tags, while interface methods are added with Method() specifying signature. The library automatically handles field alignment, tag formatting, and method signature rendering, producing properly formatted type declarations.","intents":["Generate struct type declarations with fields and tags","Create interface type declarations with method signatures","Build data structure definitions programmatically"],"best_for":["Generating model types from schemas or specifications","Creating interface definitions for code generation","Building boilerplate data structures"],"limitations":["No built-in support for embedded fields or anonymous types","Tag formatting is manual; no automatic tag generation from metadata","No support for generic types (Go 1.18+) in current versions"],"requires":["Type name and field/method specifications","Understanding of Go struct and interface syntax"],"input_types":["type name, field names/types/tags, method signatures"],"output_types":["Go struct or interface type declaration"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"github-dave--jennifer__cap_9","uri":"capability://code.generation.editing.map.and.slice.literal.generation.with.key.value.and.element.syntax","name":"map and slice literal generation with key-value and element syntax","description":"Jennifer provides Map() and Index() methods for generating map and slice literals with proper syntax. Map() creates a map literal with key-value pairs specified through method chaining, while Index() creates array/slice indexing expressions. The Values() group type renders collections with comma separators and braces, automatically handling multi-line formatting for readability. Literal values are specified using Lit() for constants or expressions for computed values.","intents":["Generate map literals with key-value pairs","Create slice and array literals with elements","Build array indexing expressions","Generate collection initializers with proper formatting"],"best_for":["Generating data initialization code","Creating lookup tables or configuration maps","Building collection-heavy code generators"],"limitations":["No built-in support for nested map/slice type inference","Large collections can produce very long lines; no automatic line breaking","No support for sparse array initialization syntax"],"requires":["Key and value types for maps","Element types for slices/arrays"],"input_types":["key-value pairs for maps, elements for slices"],"output_types":["Go map and slice literals with proper syntax"],"categories":["code-generation-editing"],"confidence":0.5,"matches":0,"success_rate":0}],"trust":{"score":41,"verified":false,"data_access_risk":"high","permissions":["Go 1.11 or later","Import github.com/dave/jennifer/jen package","File type instance created with NewFile(packageName)","Use of Qual(importPath, identifier) for qualified references","Comment text content","Valid Go identifier names","Correct import paths for Qual() references","Literal values compatible with Go types","Valid Go operator strings","Proper operand ordering for operator semantics"],"failure_modes":["Fluent chains can become deeply nested for complex code structures, reducing readability","No IDE autocomplete hints for dynamic method chains in some editors","Method chaining overhead adds ~5-10% performance cost vs direct token manipulation","Cannot detect imports needed for type assertions or interface satisfaction that aren't explicitly referenced via Qual()","Alias resolution is automatic but may produce unexpected names if not carefully managed","No support for import grouping or custom import ordering beyond standard Go conventions","No built-in support for godoc-style comment formatting","Comment content is not validated; invalid comment syntax is not detected","No automatic comment wrapping for long lines","Qual() requires explicit import path; no automatic path resolution from package names","builder identity is not verified yet","no observed match outcomes yet"],"rank_breakdown":{"adoption":0.529607829044733,"quality":0.35,"ecosystem":0.52,"match_graph":0.25,"freshness":0.52,"weights":{"adoption":0.3,"quality":0.2,"ecosystem":0.15,"match_graph":0.3,"freshness":0.05}},"observed_outcomes":{"matches":0,"success_rate":0,"avg_confidence":0,"top_intents":[],"last_matched_at":null},"maintenance":{"status":"active","updated_at":"2026-05-24T12:16:21.549Z","last_scraped_at":"2026-05-03T13:58:37.060Z","last_commit":"2024-09-08T22:27:59Z"},"community":{"stars":3614,"forks":162,"weekly_downloads":null,"model_downloads":null,"model_likes":null}},"distribution":{"claim_url":"https://unfragile.ai/submit?claim=dave--jennifer","compare_url":"https://unfragile.ai/compare?artifact=dave--jennifer"}},"signature":"ey9zR5Ub1xH1qeKLhouinO4Jz1dXE7JlWDT/bgMPK0+s6W8wrCJakX1i2bQYwnoxhG1YZ/wR5V/66lx4u5QvCQ==","signedAt":"2026-06-23T07:09:40.337Z","signedBy":"unfragile.ai","version":1},"_links":{"self":"https://unfragile.ai/api/v1/passport/dave--jennifer","artifact":"https://unfragile.ai/dave--jennifer","verify":"https://unfragile.ai/api/v1/verify?slug=dave--jennifer","publicKey":"https://unfragile.ai/api/v1/trust-passport-public-key","spec":"https://unfragile.ai/trust","schema":"https://unfragile.ai/schema.json","docs":"https://unfragile.ai/docs"}}