Support cascading modifier tags

Resolves #2056

CHANGELOG.md

@@ -41,6 +41,8 @@
 -   Added support for a `packageOptions` object which specifies options that should be applied to each entry point when running with `--entryPointStrategy packages`, #2523.
 -   `--hostedBaseUrl` will now be used to generate a `<link rel="canonical">` element in the project root page, #2550.
 -   New option, `--customFooterHtml` to add custom HTML to the generated page footer, #2559.
+-   TypeDoc will now copy modifier tags to children if specified in the `--cascadedModifierTags` option, #2056.
+-   TypeDoc will now warn if mutually exclusive modifier tags are specified for a comment (e.g. both `@alpha` and `@beta`), #2056.
 -   Added three new sort strategies `documents-first`, `documents-last`, and `alphabetical-ignoring-documents` to order markdown documents.
 -   Added new `--alwaysCreateEntryPointModule` option. When set, TypeDoc will always create a `Module` for entry points, even if only one is provided.
     If `--projectDocuments` is used to add documents, this option defaults to `true`, otherwise, defaults to `false`.

src/lib/converter/plugins/CommentPlugin.ts

@@ -24,6 +24,7 @@ import {
     removeIf,
 } from "../../utils";
 import { CategoryPlugin } from "./CategoryPlugin";
+import { setIntersection } from "../../utils/set";
 
 /**
  * These tags are not useful to display in the generated documentation.
@@ -47,6 +48,18 @@ const NEVER_RENDERED = [
     "@typedef",
 ] as const;
 
+// We might make this user configurable at some point, but for now,
+// this set is configured here.
+const MUTUALLY_EXCLUSIVE_MODIFIERS = [
+    new Set<`@${string}`>([
+        "@alpha",
+        "@beta",
+        "@experimental",
+        "@internal",
+        "@public",
+    ]),
+] as const;
+
 /**
  * Handles most behavior triggered by comments. `@group` and `@category` are handled by their respective plugins, but everything else is here.
  *
@@ -108,6 +121,9 @@ export class CommentPlugin extends ConverterComponent {
     @Option("excludeTags")
     accessor excludeTags!: `@${string}`[];
 
+    @Option("cascadedModifierTags")
+    accessor cascadedModifierTags!: `@${string}`[];
+
     @Option("excludeInternal")
     accessor excludeInternal!: boolean;
 
@@ -262,6 +278,8 @@ export class CommentPlugin extends ConverterComponent {
      * @param node  The node that is currently processed if available.
      */
     private onDeclaration(_context: Context, reflection: Reflection) {
+        this.cascadeModifiers(reflection);
+
         const comment = reflection.comment;
         if (!comment) return;
 
@@ -356,6 +374,23 @@ export class CommentPlugin extends ConverterComponent {
                 );
             }
 
+            for (const group of MUTUALLY_EXCLUSIVE_MODIFIERS) {
+                const intersect = setIntersection(
+                    group,
+                    reflection.comment.modifierTags,
+                );
+                if (intersect.size > 1) {
+                    const [a, b] = intersect;
+                    context.logger.warn(
+                        context.i18n.modifier_tag_0_is_mutually_exclusive_with_1_in_comment_for_2(
+                            a,
+                            b,
+                            reflection.getFriendlyFullName(),
+                        ),
+                    );
+                }
+            }
+
             mergeSeeTags(reflection.comment);
             movePropertyTags(reflection.comment, reflection);
         }
@@ -381,6 +416,14 @@ export class CommentPlugin extends ConverterComponent {
                     reflection.comment.removeTags("@returns");
                 }
             }
+
+            // Any cascaded tags will show up twice, once on this and once on our signatures
+            // This is completely redundant, so remove them from the wrapping function.
+            if (sigs.length) {
+                for (const mod of this.cascadedModifierTags) {
+                    reflection.comment.modifierTags.delete(mod);
+                }
+            }
         }
 
         if (reflection instanceof SignatureReflection) {
@@ -448,6 +491,29 @@ export class CommentPlugin extends ConverterComponent {
         }
     }
 
+    private cascadeModifiers(reflection: Reflection) {
+        const parentComment = reflection.parent?.comment;
+        if (!parentComment) return;
+
+        const childMods = reflection.comment?.modifierTags ?? new Set();
+
+        for (const mod of this.cascadedModifierTags) {
+            if (parentComment.hasModifier(mod)) {
+                const exclusiveSet = MUTUALLY_EXCLUSIVE_MODIFIERS.find((tags) =>
+                    tags.has(mod),
+                );
+
+                if (
+                    !exclusiveSet ||
+                    Array.from(exclusiveSet).every((tag) => !childMods.has(tag))
+                ) {
+                    reflection.comment ||= new Comment();
+                    reflection.comment.modifierTags.add(mod);
+                }
+            }
+        }
+    }
+
     /**
      * Determines whether or not a reflection has been hidden
      *

src/lib/internationalization/translatable.ts

@@ -96,6 +96,7 @@ export const translatable = {
     comment_for_0_includes_categoryDescription_for_1_but_no_child_in_group: `Comment for {0} includes @categoryDescription for "{1}", but no child is placed in that category.`,
     comment_for_0_includes_groupDescription_for_1_but_no_child_in_group: `Comment for {0} includes @groupDescription for "{1}", but no child is placed in that group.`,
     label_0_for_1_cannot_be_referenced: `The label "{0}" for {1} cannot be referenced with a declaration reference. Labels may only contain A-Z, 0-9, and _, and may not start with a number.`,
+    modifier_tag_0_is_mutually_exclusive_with_1_in_comment_for_2: `The modifier tag {0} is mutually exclusive with {1} in the comment for {2}.`,
     signature_0_has_unused_param_with_name_1: `The signature {0} has an @param with name "{1}", which was not used.`,
     declaration_reference_in_inheritdoc_for_0_not_fully_parsed: `Declaration reference in @inheritDoc for {0} was not fully parsed and may resolve incorrectly.`,
     failed_to_find_0_to_inherit_comment_from_in_1: `Failed to find "{0}" to inherit the comment from in the comment for {1}`,

src/lib/utils/options/declaration.ts

@@ -202,6 +202,7 @@ export interface TypeDocOptionMap {
     externalSymbolLinkMappings: ManuallyValidatedOption<
         Record<string, Record<string, string>>
     >;
+    cascadedModifierTags: `@${string}`[];
 
     // Organization
     categorizeByGroup: boolean;

src/lib/utils/options/sources/typedoc.ts

@@ -705,6 +705,21 @@ export function addTypeDocOptions(options: Pick<Options, "addDeclaration">) {
             }
         },
     });
+    options.addDeclaration({
+        name: "cascadedModifierTags",
+        help: (i18n) => i18n.help_modifierTags(),
+        type: ParameterType.Array,
+        defaultValue: ["@alpha", "@beta", "@experimental"],
+        validate(value, i18n) {
+            if (!Validation.validate([Array, Validation.isTagString], value)) {
+                throw new Error(
+                    i18n.option_0_values_must_be_array_of_tags(
+                        "cascadedModifierTags",
+                    ),
+                );
+            }
+        },
+    });
 
     ///////////////////////////
     // Organization Options ///

src/lib/utils/set.ts

@@ -0,0 +1,9 @@
+export function setIntersection<T>(a: Set<T>, b: Set<T>): Set<T> {
+    const result = new Set<T>();
+    for (const elem of a) {
+        if (b.has(elem)) {
+            result.add(elem);
+        }
+    }
+    return result;
+}

src/test/behavior.c2.test.ts

@@ -1205,4 +1205,24 @@ describe("Behavior Tests", () => {
         const sig2 = querySig(project, "isNonNullish");
         equal(sig2.type?.toString(), "x is NonNullable<T>");
     });
+
+    it("Cascades specified modifier tags to child reflections, #2056", () => {
+        const project = convert("cascadedModifiers");
+
+        const mods = (s: string) => query(project, s).comment?.modifierTags;
+        const sigMods = (s: string) =>
+            querySig(project, s).comment?.modifierTags;
+
+        equal(mods("BetaStuff"), new Set(["@beta"]));
+        equal(mods("BetaStuff.AlsoBeta"), new Set(["@beta"]));
+        equal(mods("BetaStuff.AlsoBeta.betaFish"), new Set());
+        equal(mods("BetaStuff.AlsoBeta.alphaFish"), new Set());
+
+        equal(sigMods("BetaStuff.AlsoBeta.betaFish"), new Set(["@beta"]));
+        equal(sigMods("BetaStuff.AlsoBeta.alphaFish"), new Set(["@alpha"]));
+
+        logger.expectMessage(
+            "warn: The modifier tag @alpha is mutually exclusive with @beta in the comment for mutuallyExclusive.",
+        );
+    });
 });

src/test/converter2/behavior/cascadedModifiers.ts

@@ -0,0 +1,14 @@
+/**
+ * @beta
+ */
+export namespace BetaStuff {
+    export class AlsoBeta {
+        betaFish() {}
+
+        /** @alpha */
+        alphaFish() {}
+    }
+}
+
+/** @alpha @beta */
+export const mutuallyExclusive = true;