[Path] Add build helpers

src/path/helpers.js

@@ -1,4 +1,4 @@
-import {ABSOLUTE_START} from './constants.js';
+import {ABSOLUTE_START, SEPARATOR} from './constants.js';
 import {isAbsolute, isRelative} from './predicates.js';
 
 /**
@@ -9,6 +9,25 @@ import {isAbsolute, isRelative} from './predicates.js';
  */
 export const absolute = (path) => isAbsolute(path) ? path : ABSOLUTE_START + path;
 
+/**
+ * Build a field path out of its individual parts.
+ *
+ * @param {...string} parts - Parts to assemble to build full path
+ * @returns {string} Assembled field path
+ */
+export const build = (...parts) => parts.join(SEPARATOR);
+
+/**
+ * Build a path to a given item inside a collection.
+ *
+ * @param {string} collectionPath - Path to the collection
+ * @param {number | string} item - Index or ID of the item
+ * @returns {string} Path to the item
+ */
+export const buildCollectionItem = (collectionPath, item) => {
+  return build(`${collectionPath}[${Number.isInteger(item) ? item : 'id:' + item}]`, 'value');
+};
+
 /**
  * Make a path relative when it is not already.
  *

src/path/helpers.test.js

@@ -1,4 +1,4 @@
-import {absolute, relative, root} from './helpers.js';
+import {absolute, build, buildCollectionItem, relative, root} from './helpers.js';
 
 describe('absolute', () => {
   test.each([
@@ -13,6 +13,36 @@ describe('absolute', () => {
   });
 });
 
+describe('build', () => {
+  test.each([
+    {parts: ['field1'], expected: 'field1'},
+    {parts: ['$.field1'], expected: '$.field1'},
+    {parts: ['level1', 'level2'], expected: 'level1.level2'},
+    {parts: ['$.level1', 'level2'], expected: '$.level1.level2'},
+    {parts: ['$.level1', 'level2', 'level3'], expected: '$.level1.level2.level3'},
+    {parts: ['$.level1.level2', 'level3'], expected: '$.level1.level2.level3'},
+    {parts: ['collection[0]', 'value', 'member'], expected: 'collection[0].value.member'},
+    {parts: ['$.collection[0]', 'value', 'member'], expected: '$.collection[0].value.member'},
+  ])('should build path: $expected', ({parts, expected}) => {
+    expect(build(...parts)).toBe(expected);
+  });
+});
+
+describe('buildCollectionItem', () => {
+  test.each([
+    {collection: 'collection', item: 0, expected: 'collection[0].value'},
+    {collection: '$.collection', item: 0, expected: '$.collection[0].value'},
+    {collection: 'collection', item: '0', expected: 'collection[id:0].value'},
+    {collection: '$.collection', item: '0', expected: '$.collection[id:0].value'},
+    {collection: '$.complex.collection', item: '0', expected: '$.complex.collection[id:0].value'},
+    {collection: 'collection', item: 'some-id', expected: 'collection[id:some-id].value'},
+    {collection: '$.collection', item: 'some-id', expected: '$.collection[id:some-id].value'},
+    {collection: '$.complex.collection', item: 'some-id', expected: '$.complex.collection[id:some-id].value'},
+  ])('should build path: $expected', ({collection, item, expected}) => {
+    expect(buildCollectionItem(collection, item)).toBe(expected);
+  });
+});
+
 describe('relative', () => {
   test.each([
     ['field1', 'field1'],

src/record/extract-collection-item.js

@@ -1,4 +1,4 @@
-import {isAbsolute, isMetadata} from '../path/index.js';
+import {buildCollectionItem, isAbsolute, isMetadata} from '../path/index.js';
 
 /**
  * Creates an instance of a relative value extractor for items of a collection field.
@@ -15,14 +15,14 @@ const extractCollectionItem = (extract, collectionPath) => (path) => {
 
 const resolvePath = (parentPath) => (path) => {
   if (Number.isInteger(path)) {
-    return `${parentPath}[${path}].value`;
+    return buildCollectionItem(parentPath, path);
   }
 
   if (isMetadata(path) || isAbsolute(path)) {
     return path;
   }
 
-  return `${parentPath}[id:${path}].value`;
+  return buildCollectionItem(parentPath, path);
 };
 
 const processPath = (resolve) => (path) => {

src/record/extract-collection-member.js

@@ -1,4 +1,4 @@
-import {isAbsolute, isMetadata} from '../path/index.js';
+import {build, buildCollectionItem, isAbsolute, isMetadata} from '../path/index.js';
 
 /**
  * Creates an instance of a relative value extractor for members of a complex collection field.
@@ -17,11 +17,7 @@ const resolvePath = (parentPath) => (item) => (path) => {
     return path;
   }
 
-  if (Number.isInteger(item)) {
-    return `${parentPath}[${item}].value.${path}`;
-  }
-
-  return `${parentPath}[id:${item}].value.${path}`;
+  return build(buildCollectionItem(parentPath, item), path);
 };
 
 const processPath = (resolve) => (path) => {

src/record/extract-member.js

@@ -16,7 +16,7 @@ const resolvePath = (parentPath) => (path) => {
   if (Path.isMetadata(path) || Path.isAbsolute(path)) {
     return path;
   }
-  return parentPath + Path.SEPARATOR + path;
+  return Path.build(parentPath, path);
 };
 
 const processPath = (resolve) => (path) => {