diff --git a/lib/coinHelpers.spec.ts b/lib/coinHelpers.spec.ts
new file mode 100644
index 0000000..61b5931
--- /dev/null
+++ b/lib/coinHelpers.spec.ts
@@ -0,0 +1,146 @@
+import { RegistryAsset } from "../types/chainRegistry";
+import { macroCoinToMicroCoin } from "./coinHelpers";
+
+const assets: readonly RegistryAsset[] = [
+  {
+    denom_units: [
+      {
+        denom: "ujunox",
+        exponent: 0,
+      },
+      {
+        denom: "junox",
+        exponent: 6,
+      },
+    ],
+    symbol: "JUNOX",
+    display: "junox",
+    name: "Juno Testnet",
+    base: "ujunox",
+  },
+  {
+    denom_units: [
+      {
+        denom: "ncheq",
+        exponent: 0,
+      },
+      {
+        denom: "cheq",
+        exponent: 9,
+      },
+    ],
+    symbol: "CHEQ",
+    display: "cheq",
+    name: "cheqd",
+    base: "ncheq",
+  },
+  {
+    denom_units: [
+      {
+        denom: "erc20/0x2Cbea61fdfDFA520Ee99700F104D5b75ADf50B0c",
+        exponent: 0,
+      },
+      {
+        denom: "arusd",
+        exponent: 18,
+      },
+    ],
+    symbol: "arUSD",
+    display: "arusd",
+    name: "Arable USD",
+    base: "erc20/0x2Cbea61fdfDFA520Ee99700F104D5b75ADf50B0c",
+  },
+  {
+    denom_units: [
+      {
+        denom: "wei",
+        exponent: 0,
+      },
+      {
+        denom: "gwei",
+        exponent: 9,
+      },
+      {
+        denom: "eth",
+        exponent: 18,
+        aliases: ["ether"],
+      },
+    ],
+    symbol: "ETH",
+    display: "eth",
+    name: "Ether",
+    base: "wei",
+  },
+];
+
+describe("macroCoinToMicroCoin", () => {
+  it("works with symbol", () => {
+    expect(macroCoinToMicroCoin({ denom: "JUNOX", amount: "12" }, assets)).toEqual({
+      denom: "ujunox",
+      amount: "12000000",
+    });
+    expect(macroCoinToMicroCoin({ denom: "CHEQ", amount: "34" }, assets)).toEqual({
+      denom: "ncheq",
+      amount: "34000000000",
+    });
+    expect(macroCoinToMicroCoin({ denom: "arUSD", amount: "56" }, assets)).toEqual({
+      denom: "erc20/0x2Cbea61fdfDFA520Ee99700F104D5b75ADf50B0c",
+      amount: "56000000000000000000",
+    });
+    expect(macroCoinToMicroCoin({ denom: "ETH", amount: "78" }, assets)).toEqual({
+      denom: "wei",
+      amount: "78000000000000000000",
+    });
+  });
+
+  it("works with base unit", () => {
+    expect(macroCoinToMicroCoin({ denom: "ujunox", amount: "12" }, assets)).toEqual({
+      denom: "ujunox",
+      amount: "12",
+    });
+    expect(macroCoinToMicroCoin({ denom: "ncheq", amount: "34" }, assets)).toEqual({
+      denom: "ncheq",
+      amount: "34",
+    });
+    expect(
+      macroCoinToMicroCoin(
+        { denom: "erc20/0x2Cbea61fdfDFA520Ee99700F104D5b75ADf50B0c", amount: "56" },
+        assets,
+      ),
+    ).toEqual({ denom: "erc20/0x2Cbea61fdfDFA520Ee99700F104D5b75ADf50B0c", amount: "56" });
+    expect(macroCoinToMicroCoin({ denom: "wei", amount: "78" }, assets)).toEqual({
+      denom: "wei",
+      amount: "78",
+    });
+  });
+
+  it("works with biggest unit", () => {
+    expect(macroCoinToMicroCoin({ denom: "junox", amount: "12" }, assets)).toEqual({
+      denom: "ujunox",
+      amount: "12000000",
+    });
+    expect(macroCoinToMicroCoin({ denom: "cheq", amount: "34" }, assets)).toEqual({
+      denom: "ncheq",
+      amount: "34000000000",
+    });
+    expect(macroCoinToMicroCoin({ denom: "arusd", amount: "56" }, assets)).toEqual({
+      denom: "erc20/0x2Cbea61fdfDFA520Ee99700F104D5b75ADf50B0c",
+      amount: "56000000000000000000",
+    });
+    expect(macroCoinToMicroCoin({ denom: "eth", amount: "78" }, assets)).toEqual({
+      denom: "wei",
+      amount: "78000000000000000000",
+    });
+  });
+
+  it("works with intermediate unit", () => {
+    expect(macroCoinToMicroCoin({ denom: "gwei", amount: "78" }, assets)).toEqual({
+      denom: "wei",
+      amount: "78000000000",
+    });
+    expect(macroCoinToMicroCoin({ denom: "GWEI", amount: "78" }, assets)).toEqual({
+      denom: "wei",
+      amount: "78000000000",
+    });
+  });
+});