- introduce new configuration flag to fetchReleaseInformation

- if enabled, it will unlock the ability to use new placeholders
  - `${{ DAYS_SINCE }}`
  - `${{ FROM_TAG_DATE }}`
  - `${{ TO_TAG_DATE }}`
- refactor to carry on the full `TagInfo` information instead of only the tagname
- refresh testcases to new apis

src/gitHelper.ts

@@ -44,6 +44,15 @@ class GitCommandManager {
     return revListOutput.stdout.trim()
   }
 
+  async tagCreation(tagName: string): Promise<string> {
+    const creationDate = await this.execGit([
+      'for-each-ref',
+      '--format="%(creatordate:rfc)"',
+      `refs/tags/${tagName}`
+    ])
+    return creationDate.stdout.trim().replace(/"/g, '')
+  }
+
   static async createCommandManager(
     workingDirectory: string
   ): Promise<GitCommandManager> {

src/main.ts

@@ -36,6 +36,8 @@ async function run(): Promise<void> {
     const ignorePreReleases = core.getInput('ignorePreReleases') === 'true'
     const failOnError = core.getInput('failOnError') === 'true'
     const fetchReviewers = core.getInput('fetchReviewers') === 'true'
+    const fetchReleaseInformation =
+      core.getInput('fetchReleaseInformation') === 'true'
     const commitMode = core.getInput('commitMode') === 'true'
 
     const result = await new ReleaseNotesBuilder(
@@ -50,6 +52,7 @@ async function run(): Promise<void> {
       failOnError,
       ignorePreReleases,
       fetchReviewers,
+      fetchReleaseInformation,
       commitMode,
       configuration
     ).build()

src/releaseNotes.ts

@@ -5,15 +5,17 @@ import {PullRequestInfo, PullRequests} from './pullRequests'
 import {Octokit} from '@octokit/rest'
 import {buildChangelog, fillAdditionalPlaceholders} from './transform'
 import {failOrError} from './utils'
+import {TagInfo} from './tags'
 
 export interface ReleaseNotesOptions {
   owner: string // the owner of the repository
   repo: string // the repository
-  fromTag: string // the tag/ref to start from
-  toTag: string // the tag/ref up to
+  fromTag: TagInfo // the tag/ref to start from
+  toTag: TagInfo // the tag/ref up to
   includeOpen: boolean // defines if we should also fetch open pull requests
   failOnError: boolean // defines if we should fail the action in case of an error
   fetchReviewers: boolean // defines if the action should fetch the reviewers for PRs - approved reviewers are not included in the default PR listing
+  fetchReleaseInformation: boolean // defines if the action should fetch the release information for the from and to tag - e.g. the creation date for the associated release
   commitMode: boolean // defines if we use the alternative commit based mode. note: this is only partially supported
   configuration: Configuration // the configuration as defined in `configuration.ts`
 }
@@ -83,7 +85,7 @@ export class ReleaseNotes {
     const commitsApi = new Commits(octokit)
     let diffInfo: DiffInfo
     try {
-      diffInfo = await commitsApi.getDiff(owner, repo, fromTag, toTag)
+      diffInfo = await commitsApi.getDiff(owner, repo, fromTag.name, toTag.name)
     } catch (error) {
       failOrError(
         `💥 Failed to retrieve - Invalid tag? - Because of: ${error}`,
@@ -212,6 +214,8 @@ export class ReleaseNotes {
           )
         }
       }
+    } else {
+      core.debug(`ℹ️ Fetching reviewers was disabled`)
     }
 
     return [diffInfo, finalPrs]

src/releaseNotesBuilder.ts

@@ -18,6 +18,7 @@ export class ReleaseNotesBuilder {
     private failOnError: boolean,
     private ignorePreReleases: boolean,
     private fetchReviewers: boolean = false,
+    private fetchReleaseInformation: boolean = false,
     private commitMode: boolean,
     private configuration: Configuration
   ) {}
@@ -61,17 +62,16 @@ export class ReleaseNotesBuilder {
       this.configuration.tag_resolver || DefaultConfiguration.tag_resolver
     )
 
-    const thisTag = tagRange.to?.name
+    let thisTag = tagRange.to
     if (!thisTag) {
       failOrError(`💥 Missing or couldn't resolve 'toTag'`, this.failOnError)
       return null
     } else {
-      this.toTag = thisTag
-      core.setOutput('toTag', thisTag)
-      core.debug(`Resolved 'toTag' as ${thisTag}`)
+      core.setOutput('toTag', thisTag.name)
+      core.debug(`Resolved 'toTag' as ${thisTag.name}`)
     }
 
-    const previousTag = tagRange.from?.name
+    let previousTag = tagRange.from
     if (previousTag == null) {
       failOrError(
         `💥 Unable to retrieve previous tag given ${this.toTag}`,
@@ -79,19 +79,39 @@ export class ReleaseNotesBuilder {
       )
       return null
     }
-    this.fromTag = previousTag
-    core.setOutput('fromTag', previousTag)
-    core.debug(`fromTag resolved via previousTag as: ${previousTag}`)
+    core.setOutput('fromTag', previousTag.name)
+    core.debug(`fromTag resolved via previousTag as: ${previousTag.name}`)
+
+    if (this.fetchReleaseInformation) {
+      // load release information from the GitHub API
+      core.info(`ℹ️ Fetching release information was enabled`)
+      thisTag = await tagsApi.fillTagInformation(
+        this.repositoryPath,
+        this.owner,
+        this.repo,
+        thisTag
+      )
+      previousTag = await tagsApi.fillTagInformation(
+        this.repositoryPath,
+        this.owner,
+        this.repo,
+        previousTag
+      )
+    } else {
+      core.debug(`ℹ️ Fetching release information was disabled`)
+    }
+
     core.endGroup()
 
     const options = {
       owner: this.owner,
       repo: this.repo,
-      fromTag: this.fromTag,
-      toTag: this.toTag,
+      fromTag: previousTag,
+      toTag: thisTag,
       includeOpen: this.includeOpen,
       failOnError: this.failOnError,
       fetchReviewers: this.fetchReviewers,
+      fetchReleaseInformation: this.fetchReleaseInformation,
       commitMode: this.commitMode,
       configuration: this.configuration
     }

src/tags.ts

@@ -6,6 +6,7 @@ import {SemVer} from 'semver'
 import {TagResolver} from './configuration'
 import {createCommandManager} from './gitHelper'
 import {RegexTransformer, validateTransformer} from './transform'
+import moment from 'moment'
 
 export interface TagResult {
   from: TagInfo | null
@@ -14,7 +15,8 @@ export interface TagResult {
 
 export interface TagInfo {
   name: string
-  commit: string
+  commit?: string
+  date?: moment.Moment
 }
 
 export interface SortableTagInfo extends TagInfo {
@@ -61,6 +63,47 @@ export class Tags {
     return tagsInfo
   }
 
+  async fillTagInformation(
+    repositoryPath: string,
+    owner: string,
+    repo: string,
+    tagInfo: TagInfo
+  ): Promise<TagInfo> {
+    const options = this.octokit.repos.getReleaseByTag.endpoint.merge({
+      owner,
+      repo,
+      tag: tagInfo.name
+    })
+
+    try {
+      const response = await this.octokit.request(options)
+      type ReleaseInformation =
+        RestEndpointMethodTypes['repos']['getReleaseByTag']['response']['data']
+
+      const release: ReleaseInformation = response.data as ReleaseInformation
+
+      tagInfo.date = moment(release.created_at)
+
+      core.info(
+        `ℹ️ Retrieved information about the release associated with ${tagInfo.name} from the GitHub API for ${owner}/${repo}`
+      )
+    } catch (error) {
+      core.info(
+        `⚠️ No release information found for ${tagInfo.name}, trying to retrieve tag creation time as fallback.`
+      )
+      const gitHelper = await createCommandManager(repositoryPath)
+      const creationTimeString = await gitHelper.tagCreation(tagInfo.name)
+      const creationTime = moment(creationTimeString)
+      if (creationTimeString !== null && creationTime.isValid()) {
+        tagInfo.date = creationTime
+        core.info(
+          `ℹ️ Resolved tag creation time (${creationTimeString}) from 'git for-each-ref --format="%(creatordate:rfc)" "refs/tags/${tagInfo.name}`
+        )
+      }
+    }
+    return tagInfo
+  }
+
   async findPredecessorTag(
     sortedTags: TagInfo[],
     repositoryPath: string,

src/transform.ts

@@ -312,11 +312,37 @@ export function fillAdditionalPlaceholders(
   // repository placeholders
   transformed = transformed.replace(/\${{OWNER}}/g, options.owner)
   transformed = transformed.replace(/\${{REPO}}/g, options.repo)
-  transformed = transformed.replace(/\${{FROM_TAG}}/g, options.fromTag)
-  transformed = transformed.replace(/\${{TO_TAG}}/g, options.toTag)
+  transformed = transformed.replace(/\${{FROM_TAG}}/g, options.fromTag.name)
+  transformed = transformed.replace(
+    /\${{FROM_TAG_SHA}}/g,
+    options.fromTag.commit || ''
+  )
+  transformed = transformed.replace(
+    /\${{FROM_TAG_DATE}}/g,
+    options.fromTag.date?.toISOString() || ''
+  )
+  transformed = transformed.replace(/\${{TO_TAG}}/g, options.toTag.name)
+  transformed = transformed.replace(
+    /\${{TO_TAG_SHA}}/g,
+    options.toTag.commit || ''
+  )
+  transformed = transformed.replace(
+    /\${{TO_TAG_DATE}}/g,
+    options.toTag.date?.toISOString() || ''
+  )
+  const fromDate = options.fromTag.date
+  const toDate = options.toTag.date
+  if (fromDate !== undefined && toDate !== undefined) {
+    transformed = transformed.replace(
+      /\${{DAYS_SINCE}}/g,
+      toDate.diff(fromDate, 'days').toString() || ''
+    )
+  } else {
+    transformed = transformed.replace(/\${{DAYS_SINCE}}/g, '')
+  }
   transformed = transformed.replace(
     /\${{RELEASE_DIFF}}/g,
-    `https://github.com/${options.owner}/${options.repo}/compare/${options.fromTag}...${options.toTag}`
+    `https://github.com/${options.owner}/${options.repo}/compare/${options.fromTag.name}...${options.toTag.name}`
   )
   return transformed
 }