Context test tools (#168)

* add enzyme test helper with lingui provider

* add router context to enzyme test helper

* get 18n, router, & config contexts rendering together in enzyme helper

* add config context to enzyme helpers

* add network and dialog contexts to enzymeHelpers

* convert OrganizationForm tests to use new mountWithContexts helper

* default all context value keys to default unless provided

* document use of mountWithContexts()

* fix typo in CONTRIBUTING.md

* update Organizations to use mountWithContext

__tests__/enzymeHelpers.jsx

@@ -0,0 +1,151 @@
+/*
+ * Enzyme helpers for injecting top-level contexts
+ * derived from https://lingui.js.org/guides/testing.html
+ */
+import React from 'react';
+import { shape, object, string, arrayOf, func } from 'prop-types';
+import { mount, shallow } from 'enzyme';
+import { I18nProvider } from '@lingui/react';
+import { ConfigProvider } from '../src/contexts/Config';
+import { _NetworkProvider } from '../src/contexts/Network';
+import { RootDialogProvider } from '../src/contexts/RootDialog';
+
+const language = 'en-US';
+const intlProvider = new I18nProvider(
+  {
+    language,
+    catalogs: {
+      [language]: {}
+    }
+  },
+  {}
+);
+const {
+  linguiPublisher: { i18n: originalI18n }
+} = intlProvider.getChildContext();
+
+const defaultContexts = {
+  linguiPublisher: {
+    i18n: {
+      ...originalI18n,
+      _: key => key.id, // provide _ macro, for just passing down the key
+      toJSON: () => '/i18n/',
+    },
+  },
+  config: {
+    ansible_version: null,
+    custom_virtualenvs: [],
+    version: null,
+    custom_logo: null,
+    custom_login_info: null,
+    toJSON: () => '/config/'
+  },
+  router: {
+    history: {
+      push: () => {},
+      replace: () => {},
+      createHref: () => {},
+    },
+    route: {
+      location: {
+        hash: '',
+        pathname: '',
+        search: '',
+        state: '',
+      },
+      match: {
+        params: {},
+        isExact: false,
+        path: '',
+        url: '',
+      },
+    },
+    toJSON: () => '/router/',
+  },
+  network: {
+    api: {
+      getConfig: () => {},
+    },
+    handleHttpError: () => {},
+  },
+  dialog: {}
+};
+
+const providers = {
+  config: ConfigProvider,
+  network: _NetworkProvider,
+  dialog: RootDialogProvider,
+};
+
+function wrapContexts (node, context) {
+  let wrapped = node;
+  let isFirst = true;
+  Object.keys(providers).forEach(key => {
+    if (context[key]) {
+      const Provider = providers[key];
+      wrapped = (
+        <Provider
+          value={context[key]}
+          i18n={isFirst ? defaultContexts.linguiPublisher.i18n : null}
+        >
+          {wrapped}
+        </Provider>
+      );
+      isFirst = false;
+    }
+  });
+  return wrapped;
+}
+
+function applyDefaultContexts (context) {
+  if (!context) {
+    return defaultContexts;
+  }
+  const newContext = {};
+  Object.keys(defaultContexts).forEach(key => {
+    newContext[key] = {
+      ...defaultContexts[key],
+      ...context[key],
+    };
+  });
+  return newContext;
+}
+
+export function shallowWithContexts (node, options = {}) {
+  const context = applyDefaultContexts(options.context);
+  return shallow(wrapContexts(node, context));
+}
+
+export function mountWithContexts (node, options = {}) {
+  const context = applyDefaultContexts(options.context);
+  const childContextTypes = {
+    linguiPublisher: shape({
+      i18n: object.isRequired
+    }).isRequired,
+    config: shape({
+      ansible_version: string,
+      custom_virtualenvs: arrayOf(string),
+      version: string,
+      custom_logo: string,
+      custom_login_info: string,
+    }),
+    router: shape({
+      route: shape({
+        location: shape({}),
+        match: shape({}),
+      }).isRequired,
+      history: shape({}).isRequired,
+    }),
+    network: shape({
+      api: shape({}).isRequired,
+      handleHttpError: func.isRequired,
+    }),
+    dialog: shape({
+      title: string,
+      setRootDialogMessage: func,
+      clearRootDialogMessage: func,
+    }),
+    ...options.childContextTypes
+  };
+  return mount(wrapContexts(node, context), { context, childContextTypes });
+}