refactor: add error handling in flat mapping convertor

rudderlabs · Jun 1, 2024 · 6b5269e · 6b5269e
1 parent 71f3b06
commit 6b5269e
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Showing 6 changed files with 33 additions and 12 deletions.
diff --git a/src/engine.ts b/src/engine.ts
@@ -42,8 +42,9 @@ export class JsonTemplateEngine {
     options?: EngineOptions,
   ): Expression {
     const flatMappingAST = mappings.map((mapping) => ({
-      input: JsonTemplateEngine.parse(mapping.input, options).statements[0],
-      output: JsonTemplateEngine.parse(mapping.output, options).statements[0],
+      ...mapping,
+      inputExpr: JsonTemplateEngine.parse(mapping.input, options).statements[0],
+      outputExpr: JsonTemplateEngine.parse(mapping.output, options).statements[0],
     }));
     return convertToObjectMapping(flatMappingAST);
   }

diff --git a/src/reverse_translator.ts b/src/reverse_translator.ts
@@ -429,8 +429,8 @@ export class JsonTemplateReverseTranslator {
 
   translateObjectExpression(expr: ObjectExpression): string {
     const code: string[] = [];
-    code.push('{\n');
-    code.push(this.translateExpressions(expr.props, ',\n'));
+    code.push('{\n\t');
+    code.push(this.translateExpressions(expr.props, ',\n\t'));
     code.push('\n}');
     return code.join('');
   }

diff --git a/src/types.ts b/src/types.ts
@@ -279,7 +279,7 @@ export type FlatMappingPaths = {
   output: string;
 };
 
-export type FlatMappingAST = {
-  input: PathExpression;
-  output: PathExpression;
+export type FlatMappingAST = FlatMappingPaths & {
+  inputExpr: PathExpression;
+  outputExpr: PathExpression;
 };
diff --git a/src/utils/converter.ts b/src/utils/converter.ts
@@ -85,11 +85,14 @@ function processAllFilter(
 
 function processFlatMapping(flatMapping: FlatMappingAST, outputAST: ObjectExpression) {
   let currentOutputPropsAST = outputAST.props;
-  const currentInputAST = flatMapping.input;
+  const currentInputAST = flatMapping.inputExpr;
 
-  const numOutputParts = flatMapping.output.parts.length;
+  const numOutputParts = flatMapping.outputExpr.parts.length;
   for (let i = 0; i < numOutputParts; i++) {
-    const outputPart = flatMapping.output.parts[i];
+    if (!currentOutputPropsAST) {
+      throw new Error(`Failed to process output mapping: ${flatMapping.output}`);
+    }
+    const outputPart = flatMapping.outputExpr.parts[i];
 
     if (outputPart.type === SyntaxType.SELECTOR && outputPart.prop?.value) {
       const key = outputPart.prop.value;
@@ -105,7 +108,7 @@ function processFlatMapping(flatMapping: FlatMappingAST, outputAST: ObjectExpres
 
       const currentOutputPropAST = findOrCreateObjectPropExpression(currentOutputPropsAST, key);
       let objectExpr: ObjectExpression = currentOutputPropAST.value as ObjectExpression;
-      const nextOutputPart = flatMapping.output.parts[i + 1] as ArrayFilterExpression;
+      const nextOutputPart = flatMapping.outputExpr.parts[i + 1] as ArrayFilterExpression;
       if (nextOutputPart.filter?.type === SyntaxType.ALL_FILTER_EXPR) {
         objectExpr = processAllFilter(currentInputAST, currentOutputPropAST);
       } else if (nextOutputPart.filter?.type === SyntaxType.ARRAY_INDEX_FILTER_EXPR) {

diff --git a/test/scenarios/mappings/data.ts b/test/scenarios/mappings/data.ts
@@ -143,7 +143,14 @@ export const data: Scenario[] = [
       ],
     },
   },
-
+  {
+    containsMappings: true,
+    templatePath: 'invalid_mappings.json',
+    options: {
+      defaultPathType: PathType.JSON,
+    },
+    error: 'Failed to process output mapping',
+  },
   {
     containsMappings: true,
     templatePath: 'mappings_with_root_fields.json',

diff --git a/test/scenarios/mappings/invalid_mappings.json b/test/scenarios/mappings/invalid_mappings.json
@@ -0,0 +1,10 @@
+[
+  {
+    "input": "$.events[0]",
+    "output": "$.events[0].name"
+  },
+  {
+    "input": "$.discount",
+    "output": "$.events[0].name[*].discount"
+  }
+]