Enum CodegenError 

pub enum CodegenError {
    Config(PackagingError),
    ProjectName {
        name: String,
        reason: String,
    },
    SchemaOutsideSchemasDir {
        field: String,
        path: PathBuf,
    },
    SchemasDirMissing {
        path: PathBuf,
    },
    SchemasDirEmpty {
        path: PathBuf,
    },
    SchemasDirRead {
        path: PathBuf,
        source: Error,
    },
    SchemaRead {
        path: PathBuf,
        source: Error,
    },
    SchemaParse {
        path: PathBuf,
        source: Error,
    },
    SchemaFileName {
        path: PathBuf,
        reason: String,
    },
    UnsupportedConstruct {
        file: PathBuf,
        pointer: String,
        construct: String,
    },
    NameCollision {
        name: String,
        first_file: PathBuf,
        first_pointer: String,
        second_file: PathBuf,
        second_pointer: String,
    },
    Write {
        path: PathBuf,
        source: Error,
    },
    CheckMissing {
        path: PathBuf,
    },
    CheckDrift {
        path: PathBuf,
    },
    CheckRead {
        path: PathBuf,
        source: Error,
    },
    ManifestParse {
        source: Error,
    },
    InvalidActivityName {
        name: String,
        reason: String,
    },
    DuplicateActivity {
        name: String,
    },
    UnknownTier {
        value: String,
    },
    ActivitySchemaMissing {
        activity: String,
        role: &'static str,
        type_name: String,
        path: PathBuf,
    },
    GoldenTypeUnresolved {
        root_type: String,
        missing: String,
        file: PathBuf,
    },
    EntrySourceRead {
        path: PathBuf,
        source: Error,
    },
    ScaffoldFacts {
        path: PathBuf,
        reason: String,
    },
}

Errors produced while generating Gleam types and codecs from a workflow project’s JSON Schemas.

Every variant carries the offending file, JSON pointer, or path as structured data so callers can render actionable guidance. Schema-shape failures always name the schema file and the JSON pointer of the offending construct.

Variants

Config(PackagingError)

The project descriptor (workflow.toml) or a schema it references failed to load: missing descriptor, invalid TOML, a referenced schema file that does not exist, or invalid JSON in a referenced schema.

ProjectName

The project’s gleam.toml declares a package name that cannot prefix a generated Gleam module.

Fields

name: String

The declared package name.

reason: String

Why the name cannot be used.

SchemaOutsideSchemasDir

A workflow.toml entry references a schema outside the project’s schemas/ directory, where codegen would never see it; schema/codec drift protection requires every referenced schema to live there.

Fields

field: String

Descriptor field that declared the path, e.g. workflow[0].input_schema.

path: PathBuf

The resolved schema path.

SchemasDirMissing

The project has no schemas/ directory to generate from.

Fields

path: PathBuf

The expected schemas/ directory.

SchemasDirEmpty

The schemas/ directory exists but contains no *.json files.

Fields

path: PathBuf

The searched schemas/ directory.

SchemasDirRead

The schemas/ directory could not be listed.

Fields

path: PathBuf

The schemas/ directory that could not be listed.

source: Error

I/O failure reported while listing the directory.

SchemaRead

A schema file could not be read.

Fields

path: PathBuf

The schema file that could not be read.

source: Error

I/O failure reported while reading the file.

SchemaParse

A schema file is not valid JSON (including duplicate object keys, which would make property order ambiguous).

Fields

path: PathBuf

The schema file that failed to parse.

source: Error

JSON parsing failure reported by serde_json.

SchemaFileName

A schema file name cannot derive a Gleam type name.

Fields

path: PathBuf

The offending schema file.

reason: String

Why the file name cannot derive a type name.

UnsupportedConstruct

A schema uses a construct outside the supported v1 subset.

Fields

file: PathBuf

The schema file containing the construct.

pointer: String

JSON pointer to the offending construct ( is the document root).

construct: String

What the construct was and, where helpful, what is supported.

NameCollision

Two schema locations derive the same generated Gleam name.

Fields

name: String

The colliding generated type or constructor name.

first_file: PathBuf

Schema file of the first derivation.

first_pointer: String

JSON pointer of the first derivation.

second_file: PathBuf

Schema file of the second derivation.

second_pointer: String

JSON pointer of the second derivation.

Write

The generated module could not be written.

Fields

path: PathBuf

The module path that could not be written.

source: Error

I/O failure reported while writing.

CheckMissing

--check failed: the generated module does not exist on disk.

Fields

path: PathBuf

The expected generated module path.

CheckDrift

--check failed: the on-disk module differs from the generated output.

Fields

path: PathBuf

The drifted generated module path.

CheckRead

The on-disk module could not be read for --check comparison.

Fields

path: PathBuf

The module path that could not be read.

source: Error

I/O failure reported while reading.

ManifestParse

The activity manifest JSON emitted by the package’s manifest() export is not a valid declaration array.

Fields

source: Error

JSON parsing failure reported by serde_json.

InvalidActivityName

A declared activity name cannot name an engine activity or a generated artifact (empty, or carrying a path separator, backslash, or the deployed-name separator).

Fields

name: String

The offending activity name.

reason: String

Why the name cannot be used.

DuplicateActivity

Two declarations share an activity name; names must be unique within a package so the generated wrappers, registration entries, and workflow.toml list are unambiguous.

Fields

name: String

The duplicated activity name.

UnknownTier

A declaration carries a tier outside the supported set.

Fields

value: String

The unrecognised tier string.

ActivitySchemaMissing

A declared activity references a value type with no schemas/<type>.json document, so its codec cannot be generated.

Fields

activity: String

The activity whose type is unresolved.

role: &'static str

Which side of the activity the type is on (input or output).

type_name: String

The unresolved value type name.

path: PathBuf

The schema path that was expected to exist.

GoldenTypeUnresolved

While deriving a wire-compat golden, a value type referenced a named Gleam type absent from its schema artifact’s definitions. The schema walker emits every nested record and enum into the artifact, so this signals a generator invariant violation rather than bad author input.

Fields

root_type: String

The value type whose golden was being derived.

missing: String

The named type that could not be found in the artifact definitions.

file: PathBuf

The schema artifact whose definitions were searched.

EntrySourceRead

The test-scaffold generator could not read the workflow’s entry-module source, which it needs to derive the typed entry function and timer count.

Fields

path: PathBuf

The entry-module source path that could not be read.

source: Error

The underlying I/O error.

ScaffoldFacts

The workflow’s entry-module source does not yield the facts the test scaffold needs (no aion/workflow import, no define call, or an unidentifiable typed entry function).

Fields

path: PathBuf

The entry-module source path the facts were read from.

reason: String

Why the facts could not be derived.

Trait Implementations

impl Debug for CodegenError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for CodegenError

fn fmt(&self, __formatter: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for CodegenError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<PackagingError> for CodegenError

fn from(source: PackagingError) -> Self

Converts to this type from the input type.