Add context to JSON parse errors

src/actions-util.ts

@@ -14,6 +14,7 @@ import {
   getCodeQLDatabasePath,
   ConfigurationError,
   getEnv,
+  getErrorMessage,
 } from "./util";
 
 /**
@@ -413,11 +414,17 @@ export const persistInputs = function (env: Env = getEnv()) {
  * Restores all inputs to the action from the persisted state.
  */
 export const restoreInputs = function () {
-  const persistedInputs = core.getState(persistedInputsKey);
-  if (persistedInputs) {
-    for (const [name, value] of JSON.parse(persistedInputs)) {
-      process.env[name] = value;
+  try {
+    const persistedInputsValue = core.getState(persistedInputsKey);
+    if (persistedInputsValue) {
+      const persistedInputs = JSON.parse(persistedInputsValue);
+
+      for (const [name, value] of persistedInputs) {
+        process.env[name] = value;
+      }
     }
+  } catch (err) {
+    throw new Error(`Unable to restore inputs: ${getErrorMessage(err)}`);
   }
 };
 

src/codeql.ts

@@ -951,7 +951,13 @@ async function getCodeQLForCmd(
           },
         },
       ).exec();
-      return JSON.parse(extractorPath) as string;
+      try {
+        return JSON.parse(extractorPath) as string;
+      } catch (err) {
+        throw new Error(
+          `Failed to parse extractor path for '${language}' from CLI: ${getErrorMessage(err)}\nOutput was: ${extractorPath}`,
+        );
+      }
     },
     async resolveQueriesStartingPacks(queries: string[]): Promise<string[]> {
       const codeqlArgs = [

src/sarif/index.ts

@@ -1,6 +1,7 @@
 import * as fs from "fs";
 
 import { Logger } from "../logging";
+import { getErrorMessage } from "../util";
 
 import * as sarif from "sarif";
 
@@ -48,7 +49,13 @@ export function getToolNames(sarifFile: Partial<sarif.Log>): string[] {
  * @returns The resulting JSON value, cast to a SARIF `Log`.
  */
 export function readSarifFile(sarifFilePath: string): Partial<sarif.Log> {
-  return JSON.parse(fs.readFileSync(sarifFilePath, "utf8")) as sarif.Log;
+  try {
+    return JSON.parse(fs.readFileSync(sarifFilePath, "utf8")) as sarif.Log;
+  } catch (err) {
+    throw new Error(
+      `Parsing SARIF file at '${sarifFilePath}' failed: ${getErrorMessage(err)}`,
+    );
+  }
 }
 
 // Takes a list of paths to sarif files and combines them together,

src/tracer-config.ts

@@ -4,7 +4,7 @@ import * as path from "path";
 import { type CodeQL } from "./codeql";
 import { type Config } from "./config-utils";
 import { Logger } from "./logging";
-import { asyncSome, BuildMode } from "./util";
+import { asyncSome, BuildMode, getErrorMessage } from "./util";
 
 export type TracerConfig = {
   env: { [key: string]: string };
@@ -79,18 +79,20 @@ export async function endTracingForCluster(
 async function getTracerConfigForCluster(
   config: Config,
 ): Promise<TracerConfig> {
-  const tracingEnvVariables = JSON.parse(
-    fs.readFileSync(
-      path.resolve(
-        config.dbLocation,
-        "temp/tracingEnvironment/start-tracing.json",
-      ),
-      "utf8",
-    ),
+  const filePath = path.resolve(
+    config.dbLocation,
+    "temp/tracingEnvironment/start-tracing.json",
   );
-  return {
-    env: tracingEnvVariables,
-  };
+  try {
+    const tracingEnvVariables = JSON.parse(fs.readFileSync(filePath, "utf8"));
+    return {
+      env: tracingEnvVariables,
+    };
+  } catch (err) {
+    throw new Error(
+      `Failed to parse tracing environment from '${filePath}': ${getErrorMessage(err)}`,
+    );
+  }
 }
 
 export async function getCombinedTracerConfig(

src/util.ts

@@ -894,7 +894,13 @@ export function parseMatrixInput(
   if (matrixInput === undefined || matrixInput === "null") {
     return undefined;
   }
-  return JSON.parse(matrixInput) as { [key: string]: string };
+  try {
+    return JSON.parse(matrixInput) as { [key: string]: string };
+  } catch (err) {
+    throw new Error(
+      `Failed to parse matrix input '${matrixInput}': ${getErrorMessage(err)}`,
+    );
+  }
 }
 
 export function wrapError(error: unknown): Error {
@@ -1037,7 +1043,11 @@ export enum BuildMode {
 }
 
 export function cloneObject<T>(obj: T): T {
-  return JSON.parse(JSON.stringify(obj)) as T;
+  try {
+    return JSON.parse(JSON.stringify(obj)) as T;
+  } catch (err) {
+    throw new Error(`Cloning object failed: ${getErrorMessage(err)}`);
+  }
 }
 
 export async function cleanUpPath(file: string, name: string, logger: Logger) {