- split logic to validate and read in additional details for changelog generation into new releaseNotesBuilder

- construct main class to be as simple as possible

src/releaseNotesBuilder.ts

@@ -0,0 +1,114 @@
+import {Configuration, DefaultConfiguration} from './configuration'
+import * as github from '@actions/github'
+import * as core from '@actions/core'
+import {createCommandManager} from './gitHelper'
+import {failOrError} from './utils'
+import {Octokit} from '@octokit/rest'
+import {Tags} from './tags'
+import {ReleaseNotes} from './releaseNotes'
+
+export class ReleaseNotesBuilder {
+  constructor(
+    private token: string | null,
+    private repositoryPath: string,
+    private owner: string | null,
+    private repo: string | null,
+    private fromTag: string | null,
+    private toTag: string | null,
+    private failOnError: boolean,
+    private ignorePreReleases: boolean,
+    private configuration: Configuration
+  ) {}
+
+  async build(): Promise<string | null> {
+    // ensure to resolve the toTag if it was not provided
+    if (!this.toTag) {
+      // if not specified try to retrieve tag from github.context.ref
+      if (github.context.ref.startsWith('refs/tags/')) {
+        this.toTag = github.context.ref.replace('refs/tags/', '')
+        core.info(
+          `🔖 Resolved current tag (${this.toTag}) from the 'github.context.ref'`
+        )
+      } else {
+        // if not specified try to retrieve tag from git
+        const gitHelper = await createCommandManager(this.repositoryPath)
+        const latestTag = await gitHelper.latestTag()
+        this.toTag = latestTag
+        core.info(
+          `🔖 Resolved current tag (${this.toTag}) from 'git rev-list --tags --skip=0 --max-count=1'`
+        )
+      }
+    }
+
+    if (!this.owner) {
+      failOrError(`💥 Missing or couldn't resolve 'owner'`, this.failOnError)
+      return null
+    } else {
+      core.setOutput('owner', this.owner)
+      core.debug(`Resolved 'owner' as ${this.owner}`)
+    }
+
+    if (!this.repo) {
+      failOrError(`💥 Missing or couldn't resolve 'owner'`, this.failOnError)
+      return null
+    } else {
+      core.setOutput('repo', this.repo)
+      core.debug(`Resolved 'repo' as ${this.repo}`)
+    }
+
+    if (!this.toTag) {
+      failOrError(`💥 Missing or couldn't resolve 'toTag'`, this.failOnError)
+      return null
+    } else {
+      core.setOutput('toTag', this.toTag)
+      core.debug(`Resolved 'toTag' as ${this.toTag}`)
+    }
+    core.endGroup()
+
+    // load octokit instance
+    const octokit = new Octokit({
+      auth: `token ${this.token || process.env.GITHUB_TOKEN}`
+    })
+
+    // ensure to resolve the fromTag if it was not provided specifically
+    if (!this.fromTag) {
+      core.startGroup(`🔖 Resolve previous tag`)
+      core.debug(`fromTag undefined, trying to resolve via API`)
+      const tagsApi = new Tags(octokit)
+
+      const previousTag = await tagsApi.findPredecessorTag(
+        this.owner,
+        this.repo,
+        this.toTag,
+        this.ignorePreReleases,
+        this.configuration.max_tags_to_fetch ||
+          DefaultConfiguration.max_tags_to_fetch
+      )
+      if (previousTag == null) {
+        failOrError(
+          `💥 Unable to retrieve previous tag given ${this.toTag}`,
+          this.failOnError
+        )
+        return null
+      }
+      this.fromTag = previousTag.name
+      core.debug(`fromTag resolved via previousTag as: ${previousTag.name}`)
+      core.endGroup()
+    }
+
+    const releaseNotes = new ReleaseNotes(octokit, {
+      owner: this.owner,
+      repo: this.repo,
+      fromTag: this.fromTag,
+      toTag: this.toTag,
+      failOnError: this.failOnError,
+      configuration: this.configuration
+    })
+
+    return (
+      (await releaseNotes.pull()) ||
+      this.configuration.empty_template ||
+      DefaultConfiguration.empty_template
+    )
+  }
+}