Refine checking of index map validity

This refactors validity checking to be recursive, so that the sub-maps in an index map can be checked recursively. Note that this allows arbitrarily nested index maps, but it's not clear if this is intended by the spec or not.
jkup · May 22, 2024 · 4bb9c73 · 4bb9c73
1 parent 1a1f618
commit 4bb9c73
Showing 1 changed file with 59 additions and 42 deletions.
diff --git a/src/validators/SourceMapFormatValidator.ts b/src/validators/SourceMapFormatValidator.ts
@@ -2,54 +2,71 @@ import { Validator } from "../util/Validator.js";
 import { ValidationResult } from "../util/ValidationResult.js";
 import type { ValidationContext } from "../util/ValidationContext.js";
 
-export class SourceMapFormatValidator extends Validator {
-  validate({ sourceMap }: ValidationContext): ValidationResult {
-    const errors: Error[] = [];
+// Defined separately from the validator class below in order to enable easier
+// recursive calls.
+function validateSourceMap(sourceMap : any) : Error[] {
+  const errors: Error[] = [];
 
-    if (sourceMap.version !== 3) {
-      errors.push(new Error("Source map version is not 3."));
+  if (sourceMap.version !== 3) {
+    errors.push(new Error(`Source map version is not 3, got ${sourceMap.version}.`));
+  }
+
+  if ("sections" in sourceMap) {
+    if ("mappings" in sourceMap) {
+      errors.push(new Error('Source map cannot have both "mappings" and "sections" fields.'));
     }
 
-    if ("sections" in sourceMap) {
-      if ("mappings" in sourceMap) {
-        errors.push(new Error('Source map cannot have both "mappings" and "sections" fields.'));
-      }
+    if (typeof sourceMap.sections !== "object") {
+      errors.push(new Error('Source map "sections" field is not an object.'));
+    } else {
+      sourceMap.sections.forEach((section: any, i: number) => {
+        if (!section.map || !(typeof section.map === "object" && section.map !== null)) {
+          errors.push(new Error(`Index map section ${i} is missing a "map" field or it is invalid.`));
+        } else {
+          // NB: this allows arbitrarily nested index maps, but is that
+          // intended by the spec?
+          const subErrors = validateSourceMap(section.map);
+          errors.push(...subErrors);
+        }
+      });
+    }
+  } else {
+    if (!sourceMap.sources || !Array.isArray(sourceMap.sources)) {
+      errors.push(new Error('Source map "sources" field is invalid or missing.'));
+    } else {
+      sourceMap.sources.forEach((x: unknown, i: number) => {
+        if (typeof x !== "string" && x !== null) errors.push(new Error(`There is a source with an invalid format on the index ${i}. Each source should be defined as a string or null`))
+      })
+    }
 
-      if (typeof sourceMap.sections !== "object") {
-        errors.push(new Error('Source map "sections" field is not an object.'));
-      }
+    if (!sourceMap.names || !Array.isArray(sourceMap.names)) {
+      errors.push(new Error('Source map "names" field is missing.'));
     } else {
-      if (!sourceMap.sources || !Array.isArray(sourceMap.sources)) {
-        errors.push(new Error('Source map "sources" field is invalid or missing.'));
-      } else {
-        sourceMap.sources.forEach((x: unknown, i: number) => {
-          if (typeof x !== "string" && x !== null) errors.push(new Error(`There is a source with an invalid format on the index ${i}. Each source should be defined as a string or null`))
-        })
-      }
-
-      if (!sourceMap.names || !Array.isArray(sourceMap.names)) {
-        errors.push(new Error('Source map "names" field is missing.'));
-      } else {
-        sourceMap.names.forEach((x: unknown, i: number) => {
-          if (typeof x !== "string") errors.push(new Error(`There is a name with an invalid format on the index ${i}. Each name should be defined as a string`))
-        })
-      }
-
-      if (!("mappings" in sourceMap)) {
-        errors.push(new Error('Source map "mappings" field is missing.'));
-      } else if (typeof sourceMap.mappings !== "string") {
-        errors.push(new Error('Source map "mappings" field is not a string.'));
-      }
-
-      if ('sourcesContent' in sourceMap) {
-        if (!Array.isArray(sourceMap.sourcesContent))
-          errors.push(new Error('Source map "sources" field is invalid.'));
-        sourceMap.sourcesContent.forEach((x: unknown, i: number) => {
-          if (x !== null && typeof x !== "string") errors.push(new Error(`There is a source content with an invalid format on the index ${i}. Each content should be defined as a strings or null`))
-        })
-      }
+      sourceMap.names.forEach((x: unknown, i: number) => {
+        if (typeof x !== "string") errors.push(new Error(`There is a name with an invalid format on the index ${i}. Each name should be defined as a string`))
+      })
     }
 
-    return ValidationResult.from(errors);
+    if (!("mappings" in sourceMap)) {
+      errors.push(new Error('Source map "mappings" field is missing.'));
+    } else if (typeof sourceMap.mappings !== "string") {
+      errors.push(new Error('Source map "mappings" field is not a string.'));
+    }
+
+    if ('sourcesContent' in sourceMap) {
+      if (!Array.isArray(sourceMap.sourcesContent))
+        errors.push(new Error('Source map "sources" field is invalid.'));
+      sourceMap.sourcesContent.forEach((x: unknown, i: number) => {
+        if (x !== null && typeof x !== "string") errors.push(new Error(`There is a source content with an invalid format on the index ${i}. Each content should be defined as a strings or null`))
+      })
+    }
+  }
+
+  return errors;
+}
+
+export class SourceMapFormatValidator extends Validator {
+  validate({ sourceMap }: ValidationContext): ValidationResult {
+    return ValidationResult.from(validateSourceMap(sourceMap));
   }
 }