Configuration
Driver specific configuration option and instructions can be found on their individual pages.
code generation is configured through a yaml configuration file (defaults to ./bobgen.yaml in the current directory). A different configuration file can be passed with the -c or --config flag.
The configuration is unmarshalled into the following Config struct.
// Config for the running of the commands
type Config struct {
// Convention and library used for handling null and optional types
// available options are:
// - "github.com/aarondl/opt" (default)
// * Uses null.Val[T] for optional values
// * Uses null.Null[T] for nullable values
// - "database/sql"
// * Uses pointers for optional values
// * Uses sql.Null[T] for nullable values
TypeSystem string `yaml:"type_system"`
// Struct tags to generate
Tags []string `yaml:"tags"`
// Disable generating factories for models
NoFactory bool `yaml:"no_factory"`
// Disable generating go test files
NoTests bool `yaml:"no_tests"`
// Disable back referencing in the loaded relationship structs
NoBackReferencing bool `yaml:"no_back_referencing"`
// Decides the casing for go structure tag names. camel, title or snake (default snake)
StructTagCasing string `yaml:"struct_tag_casing"`
// Relationship struct tag name
RelationTag string `yaml:"relation_tag"`
// List of column names that should have tags values set to '-' (ignored during parsing)
TagIgnore []string `yaml:"tag_ignore"`
Types drivers.Types `yaml:"types"` // register custom types
Aliases Aliases `yaml:"aliases"` // customize aliases
Constraints Constraints `yaml:"constraints"` // define additional constraints
Relationships Relationships `yaml:"relationships"` // define additional relationships
Replacements []Replace `yaml:"replacements"`
Inflections Inflections `yaml:"inflections"`
// Customize the generator name in the top level comment of generated files
// >> Code generated by **GENERATOR NAME**. DO NOT EDIT.
// defaults to "BobGen [driver] [version]"
Generator string `yaml:"generator"`
}
| Name | Description | Default |
|---|---|---|
| type_system | How to handle optional and nullable types. Available options are github.com/aarondl/opt and database/sql | "github.com/aarondl/opt" |
| tags | Struct tags to generate | [] |
| no_factory | Disable generating factories for models | false |
| no_tests | Disable generating go test files | false |
| no_back_referencing | If this is set to true, when relationships are loaded, the parent is not added to the loaded object's relations | false |
| wipe | If to delete the output folder before generation | false |
| struct_tag_casing | Decides the casing for go structure tag names. camel, title or snake (default snake) | "snake" |
| relation_tag | Struct tag for the relationship object | "-" |
| tag_ignore | List of column names that should have tags values set to '-' | [] |
| types | Register custom types. See more | "{} |
| aliases | Customize aliases. See more | {} |
| constraints | Define additional constraints. See more | {} |
| relationships | Define additional relationships. See more | {} |
| replacements | Define replacements for types. See more | [] |
| inflections | Define inflections for pluralization. See more | {} |
| generator | Customize the generator name in the top level comment of generated files | "" |
Aliases
Names are automatically generated for you. If you name your database entities properly you will likely have descriptive names generated in the end. However, in the case where the names in your database are bad AND unchangeable, or Bob's inference doesn't understand the names you do have (even though they are good and correct) you can use aliases to change the name of your tables, columns and relationships in the generated Go code.
It is not required to provide all parts of all names. Anything left out will be inferred by default.
# Although team_names works fine without configuration, we use it here for illustrative purposes
aliases:
team_names:
up_plural: "TeamNames"
up_singular: "TeamName"
down_plural: "teamNames"
down_singular: "teamName"
columns: # Columns can be aliased by name
uuid: "ID"
relationships: # Relationships can be aliased by name
team_id_fkey: "Owner"
For relationship names you can find the key Bob uses by first generating your models and then looking into the generated model file.
The key you need to use for the alias is in a comment in the modelR struct:
// videoR is where relationships are stored.
type videoR struct {
Tags TagSlice // video_tags.video_tags_tag_id_fkeyvideo_tags.video_tags_video_id_fkey
Sponsor *Sponsor // videos.videos_sponsor_id_fkey
User *User // videos.videos_user_id_fkey
}
aliases:
team:
relationships:
"video_tags.video_tags_tag_id_fkeyvideo_tags.video_tags_video_id_fkey": "MyCustomAlias"
Types
Custom types can be registered with the types key.
This will also allow you to edit the configuration of existing types, for example, to change how it is randomized by default.
When defining a type, you should provide the randomExpr. This is an expression that returns a random value of the type. It is used in factory.random_type().
There are things to note about writing the random expression:
- The expression must return a value of type
T - There is an existing variable of
fwhich is of type*faker.Faker
To prevent generating a test for the random expression, set no_randomization_test to true. This is useful for low-cardinality types like bool.
In certain cases, it is necessary to compare values of the type to determine if they are equal.
In such cases, you can provide a compareExpr which is an expression that compares two values of the type. Use the placeholders AAA and BBB as the types to be compared.
Imports
The imports key is used to specify any imports that are needed for the type.
The first import is the package that contains the type, and the rest are any other imports that are needed.
For example, for the type types.JSON[json.RawMessage], the imports will look like this:
types:
type.JSON[json.RawMessage]:
# ......
imports:
- '"encoding/json"'
- '"github.com/stephenafamo/bob/types"'
Example Types Configuration
types:
xml:
# OPTIONAL: If this type is an alias of another type
# this is useful to have custom randomization for a type e.g. xml
alias_of: "string"
# If this depends on another type, you can specify the type here
depends_on:
- "string"
# To be used in factory.random_type
# Use TYPE as a placeholder for the type
# * a variable `f` of type `faker.Faker` is available
# * another variable `limits` which is a slice of strings with any limits
# for example, a VARCHAR(255) would have limits = ["255"]
# another example, a DECIMAL(10,2) would have limits = ["10", "2"]
random_expr: |-
tag := f.Lorem().Word()
return fmt.Sprintf("<%s>%s</%s>", tag, f.Lorem().Word(), tag)
LocalType:
no_randomization_test: true
random_expr: |
localType := models.LocalType{}
return localType
# IMPORTANT: If the type is in the models package, you should specify the import alias
imports:
- 'models "github.com/path/to/models"'
type.JSON[json.RawMessage]:
# If true, a test for the random expression will not be generated
no_randomization_test: false
# Any imports that are needed for the type
imports:
- '"encoding/json"'
- '"github.com/stephenafamo/bob/types"'
# To be used in factory.random_type
# a variable `f` of type `faker.Faker` is available
# another variable `limits` which is a slice of strings with any limits
# for example, a VARCHAR(255) would have limits = ["255"]
# another example, a DECIMAL(10,2) would have limits = ["10", "2"]
random_expr: |-
s := &bytes.Buffer{}
s.WriteRune('{')
for i := range f.IntBetween(1, 5) {
if i > 0 {
fmt.Fprint(s, ", ")
}
fmt.Fprintf(s, "%q:%q", f.Lorem().Word(), f.Lorem().Word())
}
s.WriteRune('}')
return types.NewJSON[json.RawMessage](s.Bytes())`
# Imports for the random expression
random_expr_imports:
- '"bytes"'
- '"fmt"'
# CompareExpr is used to compare two values of this type
# if not provided, == is used
# Use AAA and BBB as placeholders for the two values
compare_expr: |-
bytes.Equal(AAA.Val, BBB.Val)
# Imports for the compare expression
compare_expr_imports:
- '"bytes"'
Replacements
There exists the ability to override types that the driver has inferred. The way to accomplish this is through the config file.
replacements:
- tables: ["table_name"] # What tables to look inside. Matches all tables if empty
# The match is a `gen.ColumnFilter` struct, and specifies which column to match.
# Matches are done using "logical AND" meaning all the specified conditions must be met.
#
# All string fields can be specified as a regular expression by enclosing them with /.../.
# Values are matched in a case-insensitive manner.
match:
name: "username" # Matches the column name
# name: "/id$/" # Regex is also supported (case-insensitive)
db_type: "varchar(255)" # Matches the database type
type: "string" # Matches the inferred column type
default: "NULL" # Matches the default value (case-insensitive)
comment: "The username" # Matches the column comment
nullable: true # Matches the nullable value. Defaults to false.
generated: false # Matches the generated value. Defaults to false.
autoincr: false # Matches the autoincr value. Defaults to false.
# The replace directive should either reference a pre-configured type, or a type
# defined in the `types` configuration.
replace: "mynull.String"
Constraints
It is possible to manually define additional constraints for your database. This is particularly useful if your database system or driver does not support constraints
This can also be used to create relationships since those are derived from foreign key constraints.
constraints:
pilots:
primary: # This will overwirte any existing primary key on the table
name: "pilots_pkey"
columns: [id]
uniques: # These will be added to existing unique constraints
- name: "pilot_name_unique"
columns: [name]
- name: "pilot_nickname_unique"
columns: [nickname]
foreign: # These will be added to existing foreign constraints
- name: "pilot_to_jets"
columns: [id]
foreign_table: "jets"
foreign_columns: [pilot_id]
Relationships
Relationships are automatically inferred from foreign key constraints. However, in certain cases, it is either not possible or not desirable to add a foreign key relationship.
We can manually describe relationships in the configuration:
relationships:
users: # The table name
- name: "custom_videos_relationship" # A unique identifier used to configure aliases
never_required: true # If true, the relationship would never be assumed to be required. This means that the factory will never auto-generate related objects for it.
sides:
- from: "users" # Name of the source of the relationship
to: "videos" # Table name of the other side of the relation
# mapping of columns from source to destination
columns:
- [id, user_id]
# Which side to modify, "from" or "to"
# If not set, it will try to "guess" which side to modify
# - if only one of the sides contains a primary key,
# it will choose to modify the other side
# - If (both or none) of them contains a primary key,
# it will try with "Unique" columns
# - If it still cannot choose, it defaults to "to"
modify: "" | from" | "to"
Related Through
The configuration also allows us to describe relationships that span multiple tables. We achieve this by having multiple sides.
In this example configuration, we add a relationship of users to videos through teams. The generated user model with have a Videos relation.
relationships:
users:
- name: "users_to_videos_through_teams"
sides:
- from: "users"
to: "teams"
columns: [[team_id, id]]
- from: "teams"
to: "videos"
columns: [[id, team_id]]
Related Where
The configuration also allows us to describe relationships that are not only based on matching columns but also columns with static values. For example, we may want to add a relationship to teams for verified members.
relationships:
users:
- name: "users_to_videos_through_teams"
sides:
- from: "teams"
to: "users"
columns: [[id, team_id]]
to_where:
- column: "verified"
sql_value: "true"
go_value: "true"
Inflections
With inflections, you can control the rules used to generate singular/plural variants. This is useful if a certain word or suffix is used multiple times, and you do not want to create aliases for every instance.
inflections:
plural: # Rules to convert a suffix to its plural form
ium: ia
plural_exact: # Rul
