[I] CompilerHost

Host capabilities required to compile TypeSpec, extending file I/O with module loading, source-kind detection, standard-library discovery, and log delivery.

Extends

• SystemHost

Properties

Property	Type	Description
logSink	LogSink	Receives processed log messages produced by compiler logging.
parseCache?	WeakMap<SourceFile, TypeSpecScriptNode>	Optional cache to reuse the results of parsing and binding across programs. Entries are keyed by source-file identity, not path; reuse a source snapshot only while its text is unchanged.

Methods

fileURLToPath()

fileURLToPath(url): string;

Converts a file URL into a path understood by this host’s file-system operations.

Parameters

Parameter	Type
url	string

Returns

string

---

getExecutionRoot()

getExecutionRoot(): string;

Returns the compiler’s installation root, used to locate bundled compiler resources.

Returns

string

---

getJsImport()

getJsImport(path): Promise<Record<string, any>>;

Loads a JavaScript module and returns its module namespace object, including TypeSpec hook exports.

Parameters

Parameter	Type
path	string

Returns

Promise<Record<string, any>>

---

getLibDirs()

getLibDirs(): string[];

Returns directories containing standard-library entry points to load for compilation.

Returns

string[]

---

getSourceFileKind()

getSourceFileKind(path): SourceFileKind | undefined;

Classifies a source path for loading, or returns undefined when the host does not recognize it.

Parameters

Parameter	Type
path	string

Returns

SourceFileKind | undefined

---

mkdirp()

mkdirp(path): Promise<string | undefined>;

create directory recursively.

Parameters

Parameter	Type	Description
path	string	Path to the directory.

Returns

Promise<string | undefined>

Inherited from

SystemHost.mkdirp

---

pathToFileURL()

pathToFileURL(path): string;

Converts a host file-system path into a file URL.

Parameters

Parameter	Type
path	string

Returns

string

---

readDir()

readDir(path): Promise<string[]>;

Read directory.

Parameters

Parameter	Type	Description
path	string	Path to the directory.

Returns

Promise<string[]>

list of file/directory in the given directory. Returns the name not the full path.

Inherited from

SystemHost.readDir

---

readFile()

readFile(path): Promise<SourceFile>;

read a utf-8 or utf-8 with bom encoded file

Parameters

Parameter	Type
path	string

Returns

Promise<SourceFile>

Inherited from

SystemHost.readFile

---

readUrl()

readUrl(url): Promise<SourceFile>;

read a file at the given url.

Parameters

Parameter	Type
url	string

Returns

Promise<SourceFile>

Inherited from

SystemHost.readUrl

---

realpath()

realpath(path): Promise<string>;

Resolves a possibly symlinked path to its real file-system path.

Parameters

Parameter	Type
path	string

Returns

Promise<string>

Inherited from

SystemHost.realpath

---

rm()

rm(path, options?): Promise<void>;

Deletes a directory or file.

Parameters

Parameter	Type	Description
path	string	Path to the directory or file.
options?	RmOptions	-

Returns

Promise<void>

Inherited from

SystemHost.rm

---

stat()

stat(path): Promise<{
  isDirectory: boolean;
  isFile: boolean;
}>;

Inspects a path; the returned predicates identify directories and regular files respectively.

Parameters

Parameter	Type
path	string

Returns

Promise<{ isDirectory: boolean; isFile: boolean; }>

Inherited from

SystemHost.stat

---

writeFile()

writeFile(path, content): Promise<void>;

Write the file.

Parameters

Parameter	Type	Description
path	string	Path to the file.
content	string	Content of the file.

Returns

Promise<void>

Inherited from

SystemHost.writeFile