feat: add TruncateAddress component to component library

Author: aaronbassett

packages/component-library/src/TruncateAddress/index.module.scss

@@ -0,0 +1,32 @@
+@use "@pythnetwork/component-library/theme";
+
+.srOnly {
+  @include theme.sr-only;
+}
+
+.truncateAddressDynamic {
+  // Defaults may get overridden by style on span
+  --min-chars-start-ch: 0ch;
+  --min-chars-end-ch: 0ch;
+
+  &::before,
+  &::after {
+    display: inline-block;
+    overflow: hidden;
+    white-space: pre;
+    max-width: 50%;
+  }
+
+  &::before {
+    content: attr(data-text-start);
+    text-overflow: ellipsis;
+    min-width: var(--min-chars-start-ch);
+  }
+
+  &::after {
+    content: attr(data-text-end);
+    text-overflow: clip;
+    direction: rtl;
+    min-width: var(--min-chars-end-ch);
+  }
+}

packages/component-library/src/TruncateAddress/index.stories.tsx

@@ -0,0 +1,168 @@
+import type { Meta, StoryObj } from "@storybook/react";
+import { TruncateAddress as TruncateAddressComponent } from "./index"; // Only import the main component
+
+const meta = {
+  component: TruncateAddressComponent,
+  argTypes: {
+    text: {
+      control: "text",
+      description: "The address string to truncate.",
+      table: {
+        category: "Data",
+      },
+    },
+    fixed: {
+      control: "boolean",
+      description:
+        "Determines if the truncation uses a fixed number of characters (true) or is dynamic (false).",
+      table: {
+        category: "Behavior",
+        defaultValue: { summary: "false" },
+      },
+    },
+    minCharsStart: {
+      control: "number",
+      description:
+        "Minimum characters to show at the start. Default for dynamic is 0, for fixed is 6.",
+      table: {
+        category: "Behavior",
+      },
+    },
+    minCharsEnd: {
+      control: "number",
+      description:
+        "Minimum characters to show at the end. Default for dynamic is 0, for fixed is 6.",
+      table: {
+        category: "Behavior",
+      },
+    },
+  },
+  parameters: {
+    docs: {
+      description: {
+        component:
+          "A component to truncate long strings, typically addresses, in a user-friendly way. It supports both dynamic (CSS-based, responsive) and fixed (JS-based, specific character counts) truncation.",
+      },
+    },
+  },
+  tags: ["autodocs"],
+} satisfies Meta<typeof TruncateAddressComponent>;
+
+export default meta;
+
+type Story = StoryObj<typeof meta>;
+
+const defaultAddress = "0x1234567890abcdef1234567890abcdef12345678";
+const longEnsName = "verylongethereumdomainnamethatshouldbetruncated.eth";
+const shortAddress = "0xABC";
+
+export const DynamicDefault: Story = {
+  args: {
+    text: defaultAddress,
+    fixed: false,
+  },
+  name: "Dynamic (Default Behavior)",
+};
+
+export const FixedDefault: Story = {
+  args: {
+    text: defaultAddress,
+    fixed: true,
+  },
+  name: "Fixed (Default Behavior)",
+};
+
+export const DynamicCustomChars: Story = {
+  args: {
+    text: defaultAddress,
+    fixed: false,
+    minCharsStart: 4,
+    minCharsEnd: 4,
+  },
+  name: "Dynamic (Custom minChars: 4 start, 4 end)",
+};
+
+export const FixedCustomChars: Story = {
+  args: {
+    text: defaultAddress,
+    fixed: true,
+    minCharsStart: 8,
+    minCharsEnd: 8,
+  },
+  name: "Fixed (Custom minChars: 8 start, 8 end)",
+};
+
+export const DynamicEnsName: Story = {
+  args: {
+    text: longEnsName,
+    fixed: false,
+    minCharsStart: 10, // Show more for ENS names if dynamic
+    minCharsEnd: 3,
+  },
+  name: "Dynamic (ENS Name)",
+};
+
+export const FixedEnsName: Story = {
+  args: {
+    text: longEnsName,
+    fixed: true,
+    minCharsStart: 10,
+    minCharsEnd: 8, // .eth + 5 chars
+  },
+  name: "Fixed (ENS Name)",
+};
+
+export const DynamicShortAddress: Story = {
+  args: {
+    text: shortAddress,
+    fixed: false,
+    // minCharsStart/End will effectively show the whole string if it's shorter
+  },
+  name: "Dynamic (Short Address)",
+};
+
+export const FixedShortAddress: Story = {
+  args: {
+    text: shortAddress,
+    fixed: true,
+    minCharsStart: 2, // Will show 0x...BC if text is 0xABC
+    minCharsEnd: 2,
+  },
+  name: "Fixed (Short Address)",
+};
+
+export const FixedVeryShortAddressShowsAll: Story = {
+  args: {
+    text: "0x1",
+    fixed: true,
+    minCharsStart: 6,
+    minCharsEnd: 6,
+  },
+  name: "Fixed (Very Short Address, Shows All)",
+  parameters: {
+    docs: {
+      description:
+        "If the text is shorter than or equal to minCharsStart + minCharsEnd, the original text is shown.",
+    },
+  },
+};
+
+export const DynamicZeroMinChars: Story = {
+  args: {
+    text: defaultAddress,
+    fixed: false,
+    minCharsStart: 0,
+    minCharsEnd: 0,
+  },
+  name: "Dynamic (Zero minChars)",
+};
+
+export const FixedZeroMinChars: Story = {
+  args: {
+    text: defaultAddress,
+    fixed: true,
+    minCharsStart: 0,
+    minCharsEnd: 0,
+  },
+  name: "Fixed (Zero minChars, shows only ellipsis)",
+};

packages/component-library/src/TruncateAddress/index.tsx

@@ -0,0 +1,70 @@
+import React, { useMemo } from "react";
+
+import styles from "./index.module.scss";
+
+export type Props = {
+  text: string;
+  fixed?: boolean;
+  minCharsStart?: number | undefined;
+  minCharsEnd?: number | undefined;
+};
+
+export const TruncateAddress = ({ fixed = false, ...rest }: Props) => {
+  return fixed ? (
+    <TruncateAddressFixed {...rest} />
+  ) : (
+    <TruncateAddressDynamic {...rest} />
+  );
+};
+
+const TruncateAddressDynamic = ({
+  text,
+  minCharsStart = 0,
+  minCharsEnd = 0,
+}: Props) => {
+  // We're setting a minimum width using CSS 'ch' units, which are relative to the
+  // width of the '0' character. This provides a good approximation for showing
+  // a certain number of characters. However, since character widths vary
+  // (e.g., 'i' is narrower than 'W'), the exact count of visible characters
+  // might differ slightly from the specified 'ch' value.
+  const style = {
+    "--min-chars-start-ch": `${minCharsStart.toString()}ch`,
+    "--min-chars-end-ch": `${minCharsEnd.toString()}ch`,
+  } as React.CSSProperties;
+
+  return (
+    <>
+      <span
+        className={styles.truncateAddressDynamic}
+        style={style}
+        data-text-start={text.slice(0, Math.floor(text.length / 2))}
+        data-text-end={text.slice(Math.floor(text.length / 2) * -1)}
+        aria-hidden="true"
+      />
+      <span className={styles.srOnly}>{text}</span>
+    </>
+  );
+};
+
+const TruncateAddressFixed = ({
+  text,
+  minCharsStart = 6,
+  minCharsEnd = 6,
+}: Props) => {
+  const truncatedValue = useMemo(
+    () =>
+      text.length <= minCharsStart + minCharsEnd
+        ? text
+        : `${text.slice(0, minCharsStart)}…${text.slice(minCharsEnd * -1)}`,
+    [text, minCharsStart, minCharsEnd],
+  );
+
+  return truncatedValue === text ? (
+    <span>{text}</span>
+  ) : (
+    <>
+      <span aria-hidden="true">{truncatedValue}</span>
+      <span className={styles.srOnly}>{text}</span>
+    </>
+  );
+};