fix: improve error messages during parse errors.

cashapp · Oct 10, 2024 · fcb24cb · fcb24cb
1 parent 6de0651
commit fcb24cb
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Showing 4 changed files with 28 additions and 12 deletions.
diff --git a/core/src/main/kotlin/cash/grammar/kotlindsl/model/DependencyDeclaration.kt b/core/src/main/kotlin/cash/grammar/kotlindsl/model/DependencyDeclaration.kt
@@ -114,8 +114,23 @@ public data class DependencyDeclaration(
     FILE,
     FILES,
     FILE_TREE,
+    GRADLE_DISTRIBUTION,
     MODULE,
     PROJECT,
     ;
+
+    public fun or(identifier: Identifier): Type {
+      return if (identifier.path in GRADLE_DISTRIBUTIONS) {
+        GRADLE_DISTRIBUTION
+      } else {
+        // In this case, might just be a user-supplied function that returns a dependency declaration
+        this
+      }
+    }
+
+    private companion object {
+      /** Well-known dependencies available directly from the local Gradle distribution. */
+      val GRADLE_DISTRIBUTIONS = listOf("gradleApi()", "gradleTestKit()", "localGroovy()")
+    }
   }
 }
diff --git a/core/src/main/kotlin/cash/grammar/kotlindsl/utils/Context.kt b/core/src/main/kotlin/cash/grammar/kotlindsl/utils/Context.kt
@@ -10,15 +10,13 @@ import org.antlr.v4.runtime.misc.Interval
 public object Context {
 
   /**
-   * Returns the "full text", from [input], represented by [this][ParserRuleContext]. The full text
-   * includes tokens that are sent to hidden channels by the lexer. cf.
-   * [ParserRuleContext.text][ParserRuleContext.getText], which only considers tokens which have
-   * been added to the parse tree (i.e., not comments or whitespace).
+   * Returns the "full text", from [input], represented by [this][ParserRuleContext]. The full text includes tokens that
+   * are sent to hidden channels by the lexer. cf. [ParserRuleContext.text][ParserRuleContext.getText], which only
+   * considers tokens which have been added to the parse tree (i.e., not comments or whitespace).
    *
-   * Returns null if `this` has a null [ParserRuleContext.start] or [ParserRuleContext.stop], which
-   * can happen when, e.g., `this` is a
-   * [ScriptContext][com.squareup.cash.grammar.KotlinParser.ScriptContext]. (I don't
-   * fully understand why those tokens might be null.)
+   * Returns null if `this` has a null [ParserRuleContext.start] or [ParserRuleContext.stop], which can happen when,
+   * e.g., `this` is a [ScriptContext][com.squareup.cash.grammar.KotlinParser.ScriptContext]. (I don't fully understand
+   * why those tokens might be null.)
    */
   public fun ParserRuleContext.fullText(input: CharStream): String? {
     val a = start?.startIndex ?: return null

diff --git a/core/src/main/kotlin/cash/grammar/kotlindsl/utils/DependencyExtractor.kt b/core/src/main/kotlin/cash/grammar/kotlindsl/utils/DependencyExtractor.kt
@@ -185,13 +185,16 @@ public class DependencyExtractor(
     }
 
     val precedingComment = comments.getCommentsToLeft(declaration)
+    val fullText = declaration.fullText(input)
+      ?: error("Could not determine 'full text' of dependency declaration. Failed to parse expression:\n  ${declaration.text}")
 
     return DependencyDeclaration(
       configuration = configuration,
-      identifier = identifier!!,
+      identifier = identifier
+        ?: error("Could not determine dependency identifier. Failed to parse expression:\n  `$fullText`"),
       capability = capability,
-      type = type,
-      fullText = declaration.fullText(input)!!,
+      type = type.or(identifier),
+      fullText = fullText,
       precedingComment = precedingComment,
     )
   }

diff --git a/core/src/test/kotlin/cash/grammar/kotlindsl/utils/DependencyExtractorTest.kt b/core/src/test/kotlin/cash/grammar/kotlindsl/utils/DependencyExtractorTest.kt
@@ -76,7 +76,7 @@ internal class DependencyExtractorTest {
         configuration = "api",
         identifier = "gradleApi()",
         capability = Capability.DEFAULT,
-        type = Type.MODULE, // TODO: new type?
+        type = Type.GRADLE_DISTRIBUTION,
       ),
     )
   }