Fix isInternalUrl for subdomain support

Refactor / reduce plumbing

app/components/Button.js

@@ -0,0 +1,116 @@
+// @flow
+import * as React from 'react';
+import styled from 'styled-components';
+import { darken } from 'polished';
+
+const RealButton = styled.button`
+  display: inline-block;
+  margin: 0;
+  padding: 0;
+  border: 0;
+  background: ${props => props.theme.primary};
+  color: ${props => props.theme.white};
+  border-radius: 4px;
+  font-size: 15px;
+  height: 36px;
+  text-decoration: none;
+  flex-shrink: 0;
+  outline: none;
+  cursor: pointer;
+
+  &::-moz-focus-inner {
+    padding: 0;
+    border: 0;
+  }
+  &:hover {
+    background: ${props => darken(0.05, props.theme.primary)};
+  }
+
+  svg {
+    position: relative;
+    top: 0.05em;
+  }
+
+  &:disabled {
+    opacity: 0.6;
+    cursor: default;
+  }
+
+  ${props =>
+    props.light &&
+    `
+    color: ${props.theme.slate};
+    background: transparent;
+    border: 1px solid ${props.theme.slate};
+
+    &:hover {
+      background: transparent;
+      color: ${props.theme.slateDark};
+      border: 1px solid ${props.theme.slateDark};
+    }
+  `} ${props =>
+      props.neutral &&
+      `
+    background: ${props.theme.slate};
+
+    &:hover {
+      background: ${darken(0.05, props.theme.slate)};
+    }
+  `} ${props =>
+      props.danger &&
+      `
+    background: ${props.theme.danger};
+
+    &:hover {
+      background: ${darken(0.05, props.theme.danger)};
+    }
+  `};
+`;
+
+const Label = styled.span`
+  overflow: hidden;
+  white-space: nowrap;
+  text-overflow: ellipsis;
+
+  ${props => props.hasIcon && 'padding-left: 2px;'};
+`;
+
+const Inner = styled.span`
+  padding: 0 12px;
+  display: flex;
+  line-height: 28px;
+  justify-content: center;
+  align-items: center;
+
+  ${props =>
+    props.hasIcon &&
+    (props.small ? 'padding-left: 6px;' : 'padding-left: 10px;')};
+`;
+
+export type Props = {
+  type?: string,
+  value?: string,
+  icon?: React.Node,
+  className?: string,
+  children?: React.Node,
+};
+
+export default function Button({
+  type = 'text',
+  icon,
+  children,
+  value,
+  ...rest
+}: Props) {
+  const hasText = children !== undefined || value !== undefined;
+  const hasIcon = icon !== undefined;
+
+  return (
+    <RealButton {...rest}>
+      <Inner hasIcon={hasIcon}>
+        {hasIcon && icon}
+        {hasText && <Label hasIcon={hasIcon}>{children || value}</Label>}
+      </Inner>
+    </RealButton>
+  );
+}