# Transformer utilities

We do not guarantee that your configuration transformers won't break after an update. It's your responsibility to keep them up to date with new releases.

To help you write configuration transformers for webpack, @workleap/webpack-configs provide a suite of utility functions.

# Module rules

Utility functions for webpack module rules.

# matchLoaderName

Returns a matcher function that can be utilized alongside module rules utility functions. The returned matcher function will return true when it encounters a module rule with a loader matching the provided name value.

const matcher = matchLoaderName(name: string)

# Parameters

name: A module rule loader name value.

# Returns

A ModuleRuleMatcher function.

# Usage

webpack.config.js
export default {
    module: {
        rules: [
            {
                test: /\.(js|jsx|ts|tsx)/i,
                loader: "swc-loader"
            }
        ]
    }
}

transformer.ts
import { matchLoaderName } from "@workleap/webpack-configs";

const matcher = matchLoaderName("swc-loader");

# matchAssetModuleType

const matcher = matchAssetModuleType(type: AssetModuleType)

# Parameters

type: A module rule loader asset type value.

# Returns

A ModuleRuleMatcher function.

# Usage

webpack.config.js
export default {
    module: {
        rules: [
            {
                test: /\.(png|jpe?g|gif)/i,
                type: "asset/resource"
            }
        ]
    }
}

transformer.ts
import { matchAssetModuleType } from "@workleap/webpack-configs";

const matcher = matchAssetModuleType("asset/resource");

# matchTest

const matcher = matchTest(test: string | RegExp)

# Parameters

test: A module rule loader test value.

# Returns

A ModuleRuleMatcher function.

# Usage

webpack.config.js
export default {
    module: {
        rules: [
            {
                test: /\.css/i,
                use: ["style-loader", "css-loader"]
            }
        ]
    }
}

transformer.ts
import { matchTest } from "@workleap/webpack-configs";

const matcher = matchTest(/\.css/i);

# findModuleRule

Retrieve the first module rule for which the matcher function returns true. If there is more than one match, an error will be thrown.

const moduleRule = findModuleRule(config: WebpackConfig, matcher: ModuleRuleMatcher)

# Parameters

config: A webpack config
matcher: A ModuleRuleMatcher function

# Returns

A module rule if a match has been found, otherwise undefined.

# Usage

transformer.ts
import { matchAssetModuleType, findModuleRule, type WebpackConfig } from "@workleap/webpack-configs";

function transformer(config: WebpackConfig) {
    const moduleRule = findModuleRule(config, matchLoaderName("swc-loader"));

    // Update the module rule...
    moduleRule.options.parseMap = true;

    return config;
}

# findModuleRules

Retrieve any module rules for which the matcher function returns true.

const moduleRules = findModuleRules(config: WebpackConfig, matcher: ModuleRuleMatcher)

# Parameters

config: A webpack config
matcher: A ModuleRuleMatcher function

# Returns

An array of module rules

# Usage

transformer.ts
import { matchAssetModuleType, findModuleRules, type WebpackConfig } from "@workleap/webpack-configs";

function transformer(config: WebpackConfig) {
    const moduleRules = findModuleRules(config, matchLoaderName("swc-loader"));

    // Update the module rules...
    moduleRules.forEach(x => {
        x.options.parseMap = true;
    });

    return config;
}

# addBeforeModuleRule

Add the provided module rules before the matching module rule. If no matching rule has been found, an error will be thrown.

addBeforeModuleRule(config: WebpackConfig, matcher: ModuleRuleMatcher, newModuleRules: RuleSetRule[] | RuleSetUseItem[]);

# Parameters

config: A webpack config
matcher: A ModuleRuleMatcher function
newModuleRules: An array of module rules

# Returns

Nothing

# Usage

transformer.ts
import { matchAssetModuleType, addBeforeModuleRule, type WebpackConfig } from "@workleap/webpack-configs";
import type { RuleSetRule } from "webpack";

function transformer(config: WebpackConfig) {
    const swcModuleRule: RuleSetRule = {
        test: /\.(ts|tsx)/i,
        loader: "swc-loader"
    };

    addBeforeModuleRule(config, matchLoaderName("css-loader"), [swcModuleRule]);

    return config;
}

# addAfterModuleRule

Add the provided module rules after the matching module rule. If no matching rule has been found, an error will be thrown.

addAfterModuleRule(config: WebpackConfig, matcher: ModuleRuleMatcher, newModuleRules: RuleSetRule[] | RuleSetUseItem[]);

# Parameters

config: A webpack config
matcher: A ModuleRuleMatcher function
newModuleRules: An array of module rules

# Returns

Nothing

# Usage

transformer.ts
import { matchAssetModuleType, addAfterModuleRule, type WebpackConfig } from "@workleap/webpack-configs";

function transformer(config: WebpackConfig) {
    const swcModuleRule: RuleSetRule = {
        test: /\.(ts|tsx)/i,
        loader: "swc-loader"
    };

    addAfterModuleRule(config, matchLoaderName("css-loader"), [swcModuleRule]);

    return config;
}

# replaceModuleRule

Replace the matching module rule by the new one. If no matching rule has been found, an error will be thrown.

replaceModuleRule(config: WebpackConfig, matcher: ModuleRuleMatcher, newModuleRule: RuleSetRule | RuleSetUseItem)

# Parameters

config: A webpack config
matcher: A ModuleRuleMatcher function
newModuleRule: The new module rule

# Returns

Nothing

# Usage

transformer.ts
import { matchAssetModuleType, replaceModuleRule, type WebpackConfig } from "@workleap/webpack-configs";

function transformer(config: WebpackConfig) {
    const swcModuleRule: RuleSetRule = {
        test: /\.(ts|tsx)/i,
        loader: "swc-loader"
    };

    replaceModuleRule(config, matchLoaderName("babel-loader"), swcModuleRule);

    return config;
}

# removeModuleRules

Remove the matching module rules. If no matching rule has been found, an error will be thrown.

removeModuleRules(config: WebpackConfig, matcher: ModuleRuleMatcher)

# Parameters

config: A webpack config
matcher: A ModuleRuleMatcher function

# Returns

Nothing

# Usage

transformer.ts
import { matchAssetModuleType, removeModuleRules, type WebpackConfig } from "@workleap/webpack-configs";

function transformer(config: WebpackConfig) {
    removeModuleRules(config, matchLoaderName("babel-loader"));

    return config;
}

# Plugins

Utility functions for webpack plugins.

# matchConstructorName

Returns a matcher function that can be utilized alongside plugin utility functions. The returned matcher function will return true when it encounters a plugin matching the provided constructor name value.

const matcher = matchConstructorName(name: string)

# Parameters

name: A plugin constructor name.

# Returns

A PluginMatcher function.

# Usage

transformer.ts
import { matchConstructorName } from "@workleap/webpack-configs";
import HtmlWebpackPlugin from "html-webpack-plugin";

const matcher = matchConstructorName(HtmlWebpackPlugin.name);

# findPlugin

Retrieve the first plugin for which the matcher function returns true. If there is more than one match, an error will be thrown.

const plugin = findPlugin(config: WebpackConfig, matcher: PluginMatcher)

# Parameters

config: A webpack config
matcher: A PluginMatcher function

# Returns

A plugin if a match has been found, otherwise undefined.

# Usage

transformer.ts
import { matchConstructorName, findPlugin, type WebpackConfig } from "@workleap/webpack-configs";
import HtmlWebpackPlugin from "html-webpack-plugin";

function transformer(config: WebpackConfig) {
    const plugin = findPlugin(config, matchConstructorName(HtmlWebpackPlugin.name));

    // Do something with the plugin...

    return config;
}

# addBeforePlugin

Add the provided plugins before the matching plugin. If no plugin has been found, an error will be thrown.

addBeforePlugin(config: WebpackConfig, matcher: PluginMatcher, newPlugins: WebpackPlugin[])

# Parameters

config: A webpack config
matcher: A PluginMatcher function
newPlugins: An array of plugins

# Returns

Nothing

# Usage

transformer.ts
import { matchConstructorName, addBeforePlugin, type WebpackConfig } from "@workleap/webpack-configs";
import CircularDependencyPlugin from "circular-dependency-plugin";
import HtmlWebpackPlugin from "html-webpack-plugin";

function transformer(config: WebpackConfig) {
    const newPlugin = new CircularDependencyPlugin({
        exclude: /node_modules/,
        include: /src/
    });

    addBeforePlugin(config, matchConstructorName(HtmlWebpackPlugin.name), [newPlugin]);

    return config;
}

# addAfterPlugin

Add the provided plugins after the matching plugin. If no plugin has been found, an error will be thrown.

addAfterPlugin(config: WebpackConfig, matcher: PluginMatcher, newPlugins: WebpackPlugin[])

# Parameters

config: A webpack config
matcher: A PluginMatcher function
newPlugins: An array of plugins

# Returns

Nothing

# Usage

transformer.ts
import { matchConstructorName, addAfterPlugin, type WebpackConfig } from "@workleap/webpack-configs";
import CircularDependencyPlugin from "circular-dependency-plugin";
import HtmlWebpackPlugin from "html-webpack-plugin";

function transformer(config: WebpackConfig) {
    const newPlugin = new CircularDependencyPlugin({
        exclude: /node_modules/,
        include: /src/
    });

    addAfterPlugin(config, matchConstructorName(HtmlWebpackPlugin.name), [newPlugin]);

    return config;
}

# replacePlugin

Replace the matching plugin by the new one. If no plugin has been found, an error will be thrown.

replacePlugin(config: WebpackConfig, matcher: PluginMatcher, newPlugin: WebpackPlugin)

# Parameters

config: A webpack config
matcher: A PluginMatcher function
newPlugin: The new plugin instance

# Returns

Nothing

# Usage

transformer.ts
import { matchConstructorName, replacePlugin, type WebpackConfig } from "@workleap/webpack-configs";
import HtmlWebpackPlugin from "html-webpack-plugin";

function transformer(config: WebpackConfig) {
    const newPlugin = new HtmlWebpackPlugin({
        template: path.resolve("./my-custom-index.html"),
        minify: true,
        hash: true
    });

    replacePlugin(config, matchConstructorName(HtmlWebpackPlugin.name));

    return config;
}

# removePlugin

Remove the matching plugin. If no plugin has been found, an error will be thrown.

removePlugin(config: WebpackConfig, matcher: PluginMatcher)

# Parameters

config: A webpack config
matcher: A PluginMatcher function

# Returns

Nothing

# Usage

transformer.ts
import { matchConstructorName, removePlugin, type WebpackConfig } from "@workleap/webpack-configs";
import HtmlWebpackPlugin from "html-webpack-plugin";

function transformer(config: WebpackConfig) {
    removePlugin(config, matchConstructorName(HtmlWebpackPlugin.name));

    return config;
}