Merge pull request NomicFoundation#2038 from nomiclabs/solc-remapping

Print warning when user tries to use solc remapping

.changeset/tender-beers-visit.md

@@ -0,0 +1,5 @@
+---
+"hardhat": patch
+---
+
+Print warning when user tries to use solc remapping (#1877)

packages/hardhat-core/src/internal/core/config/config-loading.ts

@@ -92,6 +92,7 @@ export function loadConfigAndTasks(
 
   if (showSolidityConfigWarnings) {
     checkUnsupportedSolidityConfig(resolved);
+    checkUnsupportedRemappings(resolved);
   }
 
   return resolved;
@@ -223,7 +224,7 @@ function checkMissingSolidityConfig(userConfig: any) {
   if (userConfig.solidity === undefined) {
     console.warn(
       chalk.yellow(
-        `Solidity compiler is not configured. Version ${DEFAULT_SOLC_VERSION} will be used by default. Add a 'solidity' entry to your configuration to supress this warning.
+        `Solidity compiler is not configured. Version ${DEFAULT_SOLC_VERSION} will be used by default. Add a 'solidity' entry to your configuration to suppress this warning.
 
 Learn more about compiler configuration at https://hardhat.org/config"
 `
@@ -261,3 +262,24 @@ Learn more at https://hardhat.org/reference/solidity-support
     );
   }
 }
+
+function checkUnsupportedRemappings({ solidity }: HardhatConfig) {
+  const solcConfigs = [
+    ...solidity.compilers,
+    ...Object.values(solidity.overrides),
+  ];
+  const remappings = solcConfigs.filter(
+    ({ settings }) => settings.remappings !== undefined
+  );
+
+  if (remappings.length > 0) {
+    console.warn(
+      chalk.yellow(
+        `Solidity remappings are not currently supported; you may experience unexpected compilation results. Remove any 'remappings' fields from your configuration to suppress this warning.
+
+Learn more about compiler configuration at https://hardhat.org/config
+`
+      )
+    );
+  }
+}

packages/hardhat-core/test/fixture-projects/solidity-config-warnings/remapping-in-list.js

@@ -0,0 +1,15 @@
+module.exports = {
+  solidity: {
+    compilers: [
+      {
+        version: "0.7.0",
+        settings: {
+          remappings: [":g=/dir"],
+        },
+      },
+    ],
+    overrides: {
+      "contracts/Foo.sol": { version: "0.7.0" },
+    },
+  },
+};

packages/hardhat-core/test/fixture-projects/solidity-config-warnings/remapping-in-override.js

@@ -0,0 +1,17 @@
+module.exports = {
+  solidity: {
+    compilers: [
+      {
+        version: "0.7.0",
+      },
+    ],
+    overrides: {
+      "contracts/Foo.sol": {
+        version: "0.7.0",
+        settings: {
+          remappings: [":g=/dir"],
+        },
+      },
+    },
+  },
+};

packages/hardhat-core/test/fixture-projects/solidity-config-warnings/remapping-in-settings.js

@@ -0,0 +1,8 @@
+module.exports = {
+  solidity: {
+    version: "0.7.0",
+    settings: {
+      remappings: [":g=/dir"],
+    },
+  },
+};

packages/hardhat-core/test/internal/core/config/config-loading.ts

@@ -423,5 +423,50 @@ Hardhat plugin instead.`
       assert.equal(consoleWarnStub.callCount, 1);
       assert.include(consoleWarnStub.args[0][0], "is not fully supported yet");
     });
+
+    it("should emit a warning if there is a remapping in the compiler settings", function () {
+      loadConfigAndTasks(
+        {
+          config: "remapping-in-settings.js",
+        },
+        { showSolidityConfigWarnings: true }
+      );
+
+      assert.equal(consoleWarnStub.callCount, 1);
+      assert.include(
+        consoleWarnStub.args[0][0],
+        "remappings are not currently supported"
+      );
+    });
+
+    it("should emit a warning if there is a remapping in the list of compiler settings", function () {
+      loadConfigAndTasks(
+        {
+          config: "remapping-in-list.js",
+        },
+        { showSolidityConfigWarnings: true }
+      );
+
+      assert.equal(consoleWarnStub.callCount, 1);
+      assert.include(
+        consoleWarnStub.args[0][0],
+        "remappings are not currently supported"
+      );
+    });
+
+    it("should emit a warning if there is a remapping in the list of compiler overrides", function () {
+      loadConfigAndTasks(
+        {
+          config: "remapping-in-override.js",
+        },
+        { showSolidityConfigWarnings: true }
+      );
+
+      assert.equal(consoleWarnStub.callCount, 1);
+      assert.include(
+        consoleWarnStub.args[0][0],
+        "remappings are not currently supported"
+      );
+    });
   });
 });