@jsdocs-io/extractor/src/api-extractor/functions.ts

import * as tsm from 'ts-morph';
import {
    DeclarationKinds,
    FunctionDeclaration,
} from '../types/module-declarations';
import { formatFunctionSignature } from './format';
import { getJSDocs } from './get-jsdocs';
import { hasFunctionLikeType } from './has-function-like-type';
import { SourceProvider } from './source-provider';
import { TypeChecker } from './type-checker';

export function isFunction(
    declaration: tsm.Node
): declaration is tsm.FunctionDeclaration {
    return (
        tsm.Node.isFunctionDeclaration(declaration) &&
        (declaration.isAmbient() || declaration.isImplementation())
    );
}

export function newFunction({
    id,
    name,
    declaration,
    getSource,
    getType,
}: {
    id: string;
    name: string;
    declaration: tsm.FunctionDeclaration;
    getSource: SourceProvider;
    getType: TypeChecker;
}): FunctionDeclaration {
    const kind = DeclarationKinds.FunctionDeclaration;
    const docs = getJSDocs({ declaration });
    const source = getSource({ declaration });
    const type = getType({ declaration });
    const signature = getFunctionSignature({ name, type });

    return {
        kind,
        id,
        name,
        docs,
        source,
        signature,
        type,
    };
}

export function isFunctionExpression(
    declaration: tsm.Node
): declaration is tsm.VariableDeclaration {
    return (
        tsm.Node.isVariableDeclaration(declaration) &&
        hasFunctionLikeType(declaration)
    );
}

export function newFunctionExpression({
    id,
    name,
    declaration,
    getSource,
    getType,
}: {
    id: string;
    name: string;
    declaration: tsm.VariableDeclaration;
    getSource: SourceProvider;
    getType: TypeChecker;
}): FunctionDeclaration {
    const kind = DeclarationKinds.FunctionDeclaration;
    const docs = getJSDocs({ declaration });
    const source = getSource({ declaration });
    const type = getType({ declaration });
    const signature = getFunctionSignature({ name, type });

    return {
        kind,
        id,
        name,
        docs,
        source,
        signature,
        type,
    };
}

function getFunctionSignature({
    name,
    type,
}: {
    name: string;
    type: string;
}): string {
    const signature = `${name}: ${type}`;
    return formatFunctionSignature(signature);
}