chore(context): address review comments

docs/site/Decorators_inject.md

@@ -92,7 +92,7 @@ class MyControllerWithValues {
     @inject(binding => binding.tagNames.includes('foo'), {
       bindingComparator: (a, b) => {
         // Sort by value of `foo` tag
-        return a.tagMap.foo.localCompare(b.tagMap.foo);
+        return a.tagMap.foo.localeCompare(b.tagMap.foo);
       },
     })
     public values: string[],

packages/context/src/__tests__/unit/context-view.unit.ts

@@ -7,9 +7,9 @@ import {expect} from '@loopback/testlab';
 import {
   Binding,
   BindingScope,
+  compareBindingsByGroup,
   Context,
   ContextView,
-  compareBindingsByGroup,
   createViewGetter,
   filterByTag,
 } from '../..';
@@ -31,7 +31,7 @@ describe('ContextView', () => {
     const view = new ContextView(
       server,
       filterByTag('foo'),
-      compareBindingsByGroup('foo', ['b', 'a']),
+      compareBindingsByGroup('group', ['b', 'a']),
     );
     expect(view.bindings).to.eql([bindings[1], bindings[0]]);
   });
@@ -195,14 +195,14 @@ describe('ContextView', () => {
       server
         .bind('bar')
         .toDynamicValue(() => Promise.resolve('BAR'))
-        .tag({foo: 'a'})
+        .tag('foo', 'bar', {group: 'a'})
         .inScope(BindingScope.SINGLETON),
     );
     bindings.push(
       app
         .bind('foo')
         .to('FOO')
-        .tag({foo: 'b'}),
+        .tag('foo', 'bar', {group: 'b'}),
     );
   }
 });

packages/context/src/binding-sorter.ts

@@ -8,6 +8,11 @@ import {Binding} from './binding';
 /**
  * Compare function to sort an array of bindings.
  * It is used by `Array.prototype.sort()`.
+ *
+ * @example
+ * ```ts
+ * const compareByKey: BindingComparator = (a, b) => a.key.localeCompare(b.key);
+ * ```
  */
 export interface BindingComparator {
   /**
@@ -27,18 +32,21 @@ export interface BindingComparator {
 
 /**
  * Creates a binding compare function to sort bindings by tagged group name.
+ *
+ * @remarks
  * Two bindings are compared as follows:
  *
- * 1. Get the `group` value from binding tags, if not present, default to `''`
- * 2. If both bindings have `group` values in `orderedGroups`, honor the order
- * denoted by `orderedGroups`.
+ * 1. Get values for the given tag as `group` for bindings, if the tag is not
+ * present, default `group` to `''`.
+ * 2. If both bindings have `group` value in `orderedGroups`, honor the order
+ * specified by `orderedGroups`.
  * 3. If a binding's `group` does not exist in `orderedGroups`, it comes before
- * the one exists in `orderedGroups`.
- * 4. If both bindings have `group` values outside of `orderedGroups`, they are
+ * the one with `group` exists in `orderedGroups`.
+ * 4. If both bindings have `group` value outside of `orderedGroups`, they are
  * ordered by group names alphabetically.
  *
- * @param groupTagName Name of the tag for group
- * @param orderedGroups An array of group names as predefined orders
+ * @param groupTagName Name of the binding tag for group
+ * @param orderedGroups An array of group names as the predefined order
  */
 export function compareBindingsByGroup(
   groupTagName: string = 'group',
@@ -62,10 +70,13 @@ export function compareBindingsByGroup(
 }
 
 /**
- * Sort bindings by tagged group name
+ * Sort bindings by group names denoted by a tag and the predefined order
+ * 
  * @param bindings An array of bindings
- * @param groupTagName Tag name for group
- * @param orderedGroups An array of group names as predefined orders
+ * @param groupTagName Tag name for group, for example, we can use the value
+ * `'a'` of tag `order` as the group name for `binding.tag({order: 'a'})`.
+ *
+ * @param orderedGroups An array of group names as the predefined order
  */
 export function sortBindingsByGroup(
   bindings: Readonly<Binding<unknown>>[],

packages/context/src/context-view.ts

@@ -160,23 +160,51 @@ export class ContextView<T = unknown> extends EventEmitter
 }
 
 /**
- * Create a context view as a getter
+ * Create a context view as a getter with the given filter
+ * @param ctx Context object
+ * @param bindingFilter A function to match bindings
+ * @param session Resolution session
+ */
+export function createViewGetter<T = unknown>(
+  ctx: Context,
+  bindingFilter: BindingFilter,
+  session?: ResolutionSession,
+): Getter<T[]>;
+
+/**
+ * Create a context view as a getter with the given filter and sort matched
+ * bindings by the comparator.
  * @param ctx Context object
  * @param bindingFilter A function to match bindings
- * @param bindingComparator A function to sort matched bindings
+ * @param bindingComparator A function to compare two bindings
  * @param session Resolution session
  */
 export function createViewGetter<T = unknown>(
   ctx: Context,
   bindingFilter: BindingFilter,
-  bindingSorterOrSession?: BindingComparator | ResolutionSession,
+  bindingComparator: BindingComparator,
+  session?: ResolutionSession,
+): Getter<T[]>;
+
+/**
+ * Create a context view as a getter
+ * @param ctx Context object
+ * @param bindingFilter A function to match bindings
+ * @param bindingComparatorOrSession A function to sort matched bindings or
+ * resolution session if the comparator is not needed
+ * @param session Resolution session if the comparator is provided
+ */
+export function createViewGetter<T = unknown>(
+  ctx: Context,
+  bindingFilter: BindingFilter,
+  bindingComparatorOrSession?: BindingComparator | ResolutionSession,
   session?: ResolutionSession,
 ): Getter<T[]> {
   let bindingComparator: BindingComparator | undefined = undefined;
-  if (typeof bindingSorterOrSession === 'function') {
-    bindingComparator = bindingSorterOrSession;
-  } else if (bindingSorterOrSession instanceof ResolutionSession) {
-    session = bindingSorterOrSession;
+  if (typeof bindingComparatorOrSession === 'function') {
+    bindingComparator = bindingComparatorOrSession;
+  } else if (bindingComparatorOrSession instanceof ResolutionSession) {
+    session = bindingComparatorOrSession;
   }
 
   const view = new ContextView<T>(ctx, bindingFilter, bindingComparator);

packages/context/src/inject.ts

@@ -564,12 +564,14 @@ function resolveAsGetterByFilter(
 ) {
   assertTargetType(injection, Function, 'Getter function');
   const bindingFilter = injection.bindingSelector as BindingFilter;
-  return createViewGetter(
-    ctx,
-    bindingFilter,
-    injection.metadata.bindingComparator,
-    session,
-  );
+  return injection.metadata.bindingComparator
+    ? createViewGetter(
+        ctx,
+        bindingFilter,
+        injection.metadata.bindingComparator,
+        session,
+      )
+    : createViewGetter(ctx, bindingFilter, session);
 }
 
 /**