Parser: cover full Jai corpus

src/test/kotlin/dev/hgh/jai/parser/JaiCorpusParserTest.kt

@@ -106,7 +106,7 @@ class JaiCorpusParserTest : BasePlatformTestCase() {
 
     private companion object {
         /** Ratchet. Raise it as the grammar improves; never lower it. */
-        const val MIN_CLEAN_FILES = 650
+        const val MIN_CLEAN_FILES = 714
         const val REPORTED_ERRORS = 25
         const val REPORTED_KINDS = 20
         const val GOT_WIDTH = 14

src/test/kotlin/dev/hgh/jai/parser/JaiParserLongTailTest.kt

@@ -0,0 +1,68 @@
+package dev.hgh.jai.parser
+
+import com.intellij.psi.PsiErrorElement
+import com.intellij.psi.PsiFileFactory
+import com.intellij.psi.PsiRecursiveElementWalkingVisitor
+import com.intellij.testFramework.fixtures.BasePlatformTestCase
+import dev.hgh.jai.JaiLanguage
+
+/**
+ * Focused regressions for syntax recovered while closing the corpus gate.
+ *
+ * [JaiCorpusParserTest] proves acceptance across the full local distribution;
+ * these small examples make the individual grammar contracts easy to exercise
+ * while iterating on generated PSI.
+ */
+class JaiParserLongTailTest : BasePlatformTestCase() {
+    fun testLongTailConstructsParseWithoutErrors() {
+        val snippets =
+            listOf(
+                "result=, output, error := call();",
+                """
+                Thing :: struct {
+                    using,except SKIP_THESE field: Field;
+                }
+                proc :: (using,except(x,y,z) value: Value) {}
+                """.trimIndent(),
+                """
+                factory :: () {
+                    callback = p => { release(p); };
+                    result := { callback, p };
+                }
+                """.trimIndent(),
+                """
+                while `loop := ready { break loop; }
+                if #compile_time { report(); } else { fallback(); }
+                if (release) #if ENABLE_STATISTICS report();
+                """.trimIndent(),
+                """
+                operator ! :: inline (value: Flag) -> bool { return value; }
+                push_context,defer_pop ctx;
+                return first, second,;
+                """.trimIndent(),
+            )
+        val factory = PsiFileFactory.getInstance(project)
+
+        for ((index, text) in snippets.withIndex()) {
+            val file = factory.createFileFromText("long-tail-$index.jai", JaiLanguage, text)
+            val errors = errorsIn(file)
+            assertTrue(
+                "Long-tail snippet $index produced parser errors: ${errors.joinToString { it.errorDescription }}\n$text",
+                errors.isEmpty(),
+            )
+        }
+    }
+
+    private fun errorsIn(file: com.intellij.psi.PsiFile): List<PsiErrorElement> {
+        val errors = mutableListOf<PsiErrorElement>()
+        file.accept(
+            object : PsiRecursiveElementWalkingVisitor() {
+                override fun visitErrorElement(element: PsiErrorElement) {
+                    errors.add(element)
+                    super.visitErrorElement(element)
+                }
+            },
+        )
+        return errors
+    }
+}