[JS IR] Add CLI argument to setup error tolerance policy

-  Make sure dev mode is enabled if code with errors is allowed

js/js.frontend/src/org/jetbrains/kotlin/js/analyze/TopDownAnalyzerFacadeForJS.kt

@@ -22,6 +22,7 @@ import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.incremental.components.LookupTracker
 import org.jetbrains.kotlin.incremental.js.IncrementalDataProvider
 import org.jetbrains.kotlin.js.analyzer.JsAnalysisResult
+import org.jetbrains.kotlin.js.config.ErrorTolerancePolicy
 import org.jetbrains.kotlin.js.config.JSConfigurationKeys
 import org.jetbrains.kotlin.js.config.JsConfig
 import org.jetbrains.kotlin.js.resolve.JsPlatformAnalyzerServices
@@ -114,10 +115,14 @@ abstract class AbstractTopDownAnalyzerFacadeForJS {
         return JsAnalysisResult.success(trace, moduleContext.module)
     }
 
-    fun checkForErrors(allFiles: Collection<KtFile>, bindingContext: BindingContext) {
-        AnalyzingUtils.throwExceptionOnErrors(bindingContext)
-        for (file in allFiles) {
-            AnalyzingUtils.checkForSyntacticErrors(file)
+    fun checkForErrors(allFiles: Collection<KtFile>, bindingContext: BindingContext, errorPolicy: ErrorTolerancePolicy) {
+        if (!errorPolicy.allowSemanticErrors) {
+            AnalyzingUtils.throwExceptionOnErrors(bindingContext)
+        }
+        if (!errorPolicy.allowSyntaxErrors) {
+            for (file in allFiles) {
+                AnalyzingUtils.checkForSyntacticErrors(file)
+            }
         }
     }
 }

js/js.frontend/src/org/jetbrains/kotlin/js/config/ErrorTolerancePolicy.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.js.config
+
+enum class ErrorTolerancePolicy(val allowSyntaxErrors: Boolean, val allowSemanticErrors: Boolean) {
+    NONE(false, false),
+    SEMANTIC(false, true),
+    ALL(true, true);
+
+    val allowErrors: Boolean get() = allowSyntaxErrors || allowSemanticErrors
+
+    companion object {
+        val DEFAULT = NONE
+
+        fun resolvePolicy(key: String): ErrorTolerancePolicy {
+            return when (key.toUpperCase()) {
+                "NONE" -> NONE
+                "SEMANTIC" -> SEMANTIC
+                "SYNTAX", "ALL" -> ALL
+                else -> error("Unknown error tolerance policy '$key'")
+            }
+        }
+    }
+}

js/js.frontend/src/org/jetbrains/kotlin/js/config/JSConfigurationKeys.java

@@ -86,4 +86,7 @@ public class JSConfigurationKeys {
 
     public static final CompilerConfigurationKey<Boolean> DISABLE_FAKE_OVERRIDE_VALIDATOR =
             CompilerConfigurationKey.create("disable IR fake override validator");
+
+    public static final CompilerConfigurationKey<ErrorTolerancePolicy> ERROR_TOLERANCE_POLICY =
+            CompilerConfigurationKey.create("set up policy to ignore compilation errors");
 }