Factor out repeat compilation check and put it in encoder

packages/codec/lib/compilations/utils.ts

@@ -688,3 +688,16 @@ export function infoToCompilations(
     return shimArtifacts(projectInfo.artifacts, undefined, nonceString);
   }
 }
+
+export function findRepeatCompilationId(
+  compilations: Compilation[]
+): string | null {
+  for (let i = 0; i < compilations.length; i++) {
+    for (let j = i + 1; j < compilations.length; j++) {
+      if (compilations[i].id === compilations[j].id) {
+        return compilations[i].id;
+      }
+    }
+  }
+  return null;
+}

packages/codec/lib/errors.ts

@@ -76,3 +76,16 @@ export class NoProjectInfoError extends Error {
     this.name = "NoProjectInfoError";
   }
 }
+
+/**
+ * This error indicates there was an attempt to add multiple compilations
+ * with the same ID, or a compilation whose ID was already in use.
+ */
+export class RepeatCompilationIdError extends Error {
+  public id: string;
+  constructor(id: string) {
+    super(`Compilation id ${id} already in use.`);
+    this.id = id;
+    this.name = "RepeatCompilationIdError";
+  }
+}

packages/codec/lib/index.ts

@@ -77,7 +77,12 @@ export {
   decodeReturndata,
   decodeRevert
 } from "./core";
-export { DecodingError, StopDecodingError, NoProjectInfoError } from "./errors";
+export {
+  DecodingError,
+  StopDecodingError,
+  NoProjectInfoError,
+  RepeatCompilationIdError
+} from "./errors";
 
 //now: what types should we export? (other than the ones from ./format)
 //public-facing types for the interface

packages/decoder/lib/decoders.ts

@@ -41,8 +41,7 @@ import {
   VariableNotFoundError,
   MemberNotFoundError,
   ArrayIndexOutOfBoundsError,
-  NoProviderError,
-  RepeatCompilationIdError
+  NoProviderError
 } from "./errors";
 import { Shims } from "@truffle/compile-common";
 //sorry for the untyped import, but...
@@ -83,12 +82,10 @@ export class ProjectDecoder {
       throw new NoProviderError();
     }
     //check for repeat compilation IDs
-    for (let i = 0; i < compilations.length; i++) {
-      for (let j = i + 1; j < compilations.length; j++) {
-        if (compilations[i].id === compilations[j].id) {
-          throw new RepeatCompilationIdError(compilations[i].id);
-        }
-      }
+    const repeatId =
+      Codec.Compilations.Utils.findRepeatCompilationId(compilations);
+    if (repeatId !== null) {
+      throw new Codec.RepeatCompilationIdError(repeatId);
     }
     this.providerAdapter = new ProviderAdapter(provider);
     this.compilations = compilations;
@@ -166,15 +163,13 @@ export class ProjectDecoder {
       existingIds.has(compilation.id)
     );
     if (conflictingCompilation !== undefined) {
-      throw new RepeatCompilationIdError(conflictingCompilation.id);
+      throw new Codec.RepeatCompilationIdError(conflictingCompilation.id);
     }
     //also: check for repeats among the ones we're adding
-    for (let i = 0; i < compilations.length; i++) {
-      for (let j = i + 1; j < compilations.length; j++) {
-        if (compilations[i].id === compilations[j].id) {
-          throw new RepeatCompilationIdError(compilations[i].id);
-        }
-      }
+    const repeatId =
+      Codec.Compilations.Utils.findRepeatCompilationId(compilations);
+    if (repeatId !== null) {
+      throw new Codec.RepeatCompilationIdError(repeatId);
     }
 
     //now: checks are over, start adding stuff

packages/decoder/lib/errors.ts

@@ -174,16 +174,3 @@ export class NoProviderError extends Error {
     this.name = "NoProviderError";
   }
 }
-
-/**
- * This error indicates there was an attempt to add multiple compilations
- * with the same ID, or a compilation whose ID was already in use.
- */
-export class RepeatCompilationIdError extends Error {
-  public id: string;
-  constructor(id: string) {
-    super(`Compilation id ${id} already in use.`);
-    this.id = id;
-    this.name = "RepeatCompilationIdError";
-  }
-}

packages/encoder/lib/encoders.ts

@@ -96,6 +96,14 @@ export class ProjectEncoder {
       if (!info.compilations) {
         throw new NoInternalInfoError();
       }
+      //check for repeat compilation IDs
+      const repeatId = Codec.Compilations.Utils.findRepeatCompilationId(
+        info.compilations
+      );
+      if (repeatId !== null) {
+        throw new Codec.RepeatCompilationIdError(repeatId);
+      }
+      //since that's good, save it and continue
       this.compilations = info.compilations;
       ({
         definitions: this.referenceDeclarations,