Merge pull request #722 from 0xProject/improvement/publishing-v2

Improvements to pre-publishing checks

7 files changed, 317 insertions, 111 deletions

diff --git a/packages/monorepo-scripts/src/prepublish_checks.ts b/packages/monorepo-scripts/src/prepublish_checks.ts
index 2c096d8f6..1c4ee1fc6 100644
--- a/packages/monorepo-scripts/src/prepublish_checks.ts
+++ b/packages/monorepo-scripts/src/prepublish_checks.ts
@@ -1,9 +1,128 @@
 import * as _ from 'lodash';
 import { exec as execAsync } from 'promisify-child-process';
+import semver = require('semver');
+import semverSort = require('semver-sort');
 
 import { constants } from './constants';
+import { changelogUtils } from './utils/changelog_utils';
+import { npmUtils } from './utils/npm_utils';
 import { utils } from './utils/utils';
 
+async function prepublishChecksAsync(): Promise<void> {
+    const shouldIncludePrivate = false;
+    const updatedPublicLernaPackages = await utils.getUpdatedLernaPackagesAsync(shouldIncludePrivate);
+
+    await checkCurrentVersionMatchesLatestPublishedNPMPackageAsync(updatedPublicLernaPackages);
+    await checkChangelogFormatAsync(updatedPublicLernaPackages);
+    await checkGitTagsForNextVersionAndDeleteIfExistAsync(updatedPublicLernaPackages);
+    await checkPublishRequiredSetupAsync();
+}
+
+async function checkGitTagsForNextVersionAndDeleteIfExistAsync(
+    updatedPublicLernaPackages: LernaPackage[],
+): Promise<void> {
+    const packageNames = _.map(updatedPublicLernaPackages, lernaPackage => lernaPackage.package.name);
+    const localGitTags = await utils.getLocalGitTagsAsync();
+    const localTagVersionsByPackageName = await utils.getGitTagsByPackageNameAsync(packageNames, localGitTags);
+
+    const remoteGitTags = await utils.getRemoteGitTagsAsync();
+    const remoteTagVersionsByPackageName = await utils.getGitTagsByPackageNameAsync(packageNames, remoteGitTags);
+
+    for (const lernaPackage of updatedPublicLernaPackages) {
+        const currentVersion = lernaPackage.package.version;
+        const packageName = lernaPackage.package.name;
+        const packageLocation = lernaPackage.location;
+        const nextVersion = await utils.getNextPackageVersionAsync(currentVersion, packageName, packageLocation);
+
+        const localTagVersions = localTagVersionsByPackageName[packageName];
+        if (_.includes(localTagVersions, nextVersion)) {
+            const tagName = `${packageName}@${nextVersion}`;
+            await utils.removeLocalTagAsync(tagName);
+        }
+
+        const remoteTagVersions = remoteTagVersionsByPackageName[packageName];
+        if (_.includes(remoteTagVersions, nextVersion)) {
+            const tagName = `:refs/tags/${packageName}@${nextVersion}`;
+            await utils.removeRemoteTagAsync(tagName);
+        }
+    }
+}
+
+async function checkCurrentVersionMatchesLatestPublishedNPMPackageAsync(
+    updatedPublicLernaPackages: LernaPackage[],
+): Promise<void> {
+    utils.log('Check package versions against npmjs.org...');
+    const versionMismatches = [];
+    for (const lernaPackage of updatedPublicLernaPackages) {
+        const packageName = lernaPackage.package.name;
+        const packageVersion = lernaPackage.package.version;
+        const packageRegistryJsonIfExists = await npmUtils.getPackageRegistryJsonIfExistsAsync(packageName);
+        if (_.isUndefined(packageRegistryJsonIfExists)) {
+            continue; // noop for packages not yet published to NPM
+        }
+        const allVersionsIncludingUnpublished = npmUtils.getPreviouslyPublishedVersions(packageRegistryJsonIfExists);
+        const sortedVersions = semverSort.desc(allVersionsIncludingUnpublished);
+        const latestNPMVersion = sortedVersions[0];
+        if (packageVersion !== latestNPMVersion) {
+            versionMismatches.push({
+                packageJsonVersion: packageVersion,
+                npmVersion: latestNPMVersion,
+                packageName,
+            });
+        }
+    }
+    if (!_.isEmpty(versionMismatches)) {
+        utils.log(`Found version mismatches between package.json and NPM published versions (might be unpublished).`);
+        _.each(versionMismatches, versionMismatch => {
+            utils.log(
+                `${versionMismatch.packageName}: ${versionMismatch.packageJsonVersion} package.json, ${
+                    versionMismatch.npmVersion
+                } on NPM`,
+            );
+        });
+        throw new Error(`Please fix the above package.json/NPM inconsistencies.`);
+    }
+}
+
+async function checkChangelogFormatAsync(updatedPublicLernaPackages: LernaPackage[]): Promise<void> {
+    utils.log('Check CHANGELOGs for inconsistencies...');
+    const changeLogInconsistencies = [];
+    for (const lernaPackage of updatedPublicLernaPackages) {
+        const packageName = lernaPackage.package.name;
+        const changelog = changelogUtils.getChangelogOrCreateIfMissing(packageName, lernaPackage.location);
+
+        const currentVersion = lernaPackage.package.version;
+        if (!_.isEmpty(changelog)) {
+            const lastEntry = changelog[0];
+            const doesLastEntryHaveTimestamp = !_.isUndefined(lastEntry.timestamp);
+            if (semver.lt(lastEntry.version, currentVersion)) {
+                changeLogInconsistencies.push({
+                    packageJsonVersion: currentVersion,
+                    changelogVersion: lastEntry.version,
+                    packageName,
+                });
+            } else if (semver.gt(lastEntry.version, currentVersion) && doesLastEntryHaveTimestamp) {
+                // Remove incorrectly added timestamp
+                delete changelog[0].timestamp;
+                // Save updated CHANGELOG.json
+                await changelogUtils.writeChangelogJsonFileAsync(lernaPackage.location, changelog);
+                utils.log(`${packageName}: Removed timestamp from latest CHANGELOG.json entry.`);
+            }
+        }
+    }
+    if (!_.isEmpty(changeLogInconsistencies)) {
+        utils.log(`CHANGELOG versions cannot below package.json versions:`);
+        _.each(changeLogInconsistencies, inconsistency => {
+            utils.log(
+                `${inconsistency.packageName}: ${inconsistency.packageJsonVersion} package.json, ${
+                    inconsistency.changelogVersion
+                } CHANGELOG.json`,
+            );
+        });
+        throw new Error('Fix the above inconsistencies to continue.');
+    }
+}
+
 async function checkPublishRequiredSetupAsync(): Promise<void> {
     // check to see if logged into npm before publishing
     try {
@@ -65,7 +184,7 @@ async function checkPublishRequiredSetupAsync(): Promise<void> {
     }
 }
 
-checkPublishRequiredSetupAsync().catch(err => {
+prepublishChecksAsync().catch(err => {
     utils.log(err.message);
     process.exit(1);
 });
diff --git a/packages/monorepo-scripts/src/publish.ts b/packages/monorepo-scripts/src/publish.ts
index 2efbc8bf2..72c6c0a71 100644
--- a/packages/monorepo-scripts/src/publish.ts
+++ b/packages/monorepo-scripts/src/publish.ts
@@ -1,18 +1,17 @@
 #!/usr/bin/env node
 
 import * as promisify from 'es6-promisify';
-import * as fs from 'fs';
 import * as _ from 'lodash';
 import * as moment from 'moment';
 import opn = require('opn');
-import * as path from 'path';
 import { exec as execAsync, spawn } from 'promisify-child-process';
 import * as prompt from 'prompt';
+import semver = require('semver');
 import semverDiff = require('semver-diff');
 import semverSort = require('semver-sort');
 
 import { constants } from './constants';
-import { Changelog, PackageToVersionChange, SemVerIndex, VersionChangelog } from './types';
+import { PackageToVersionChange, SemVerIndex, VersionChangelog } from './types';
 import { changelogUtils } from './utils/changelog_utils';
 import { utils } from './utils/utils';
 
@@ -119,25 +118,23 @@ async function updateChangeLogsAsync(updatedPublicLernaPackages: LernaPackage[])
     const packageToVersionChange: PackageToVersionChange = {};
     for (const lernaPackage of updatedPublicLernaPackages) {
         const packageName = lernaPackage.package.name;
-        const changelogJSONPath = path.join(lernaPackage.location, 'CHANGELOG.json');
-        const changelogJSON = utils.getChangelogJSONOrCreateIfMissing(changelogJSONPath);
-        let changelog: Changelog;
-        try {
-            changelog = JSON.parse(changelogJSON);
-        } catch (err) {
-            throw new Error(
-                `${lernaPackage.package.name}'s CHANGELOG.json contains invalid JSON. Please fix and try again.`,
-            );
-        }
+        let changelog = changelogUtils.getChangelogOrCreateIfMissing(packageName, lernaPackage.location);
 
         const currentVersion = lernaPackage.package.version;
-        const shouldAddNewEntry = changelogUtils.shouldAddNewChangelogEntry(currentVersion, changelog);
+        const shouldAddNewEntry = changelogUtils.shouldAddNewChangelogEntry(
+            lernaPackage.package.name,
+            currentVersion,
+            changelog,
+        );
         if (shouldAddNewEntry) {
             // Create a new entry for a patch version with generic changelog entry.
-            const nextPatchVersion = utils.getNextPatchVersion(currentVersion);
+            const nextPatchVersionIfValid = semver.inc(currentVersion, 'patch');
+            if (_.isNull(nextPatchVersionIfValid)) {
+                throw new Error(`Encountered invalid semver version: ${currentVersion} for package: ${packageName}`);
+            }
             const newChangelogEntry: VersionChangelog = {
                 timestamp: TODAYS_TIMESTAMP,
-                version: nextPatchVersion,
+                version: nextPatchVersionIfValid,
                 changes: [
                     {
                         note: 'Dependencies updated',
@@ -145,7 +142,7 @@ async function updateChangeLogsAsync(updatedPublicLernaPackages: LernaPackage[])
                 ],
             };
             changelog = [newChangelogEntry, ...changelog];
-            packageToVersionChange[packageName] = semverDiff(currentVersion, nextPatchVersion);
+            packageToVersionChange[packageName] = semverDiff(currentVersion, nextPatchVersionIfValid);
         } else {
             // Update existing entry with timestamp
             const lastEntry = changelog[0];
@@ -160,14 +157,11 @@ async function updateChangeLogsAsync(updatedPublicLernaPackages: LernaPackage[])
         }
 
         // Save updated CHANGELOG.json
-        fs.writeFileSync(changelogJSONPath, JSON.stringify(changelog, null, '\t'));
-        await utils.prettifyAsync(changelogJSONPath, constants.monorepoRootPath);
+        await changelogUtils.writeChangelogJsonFileAsync(lernaPackage.location, changelog);
         utils.log(`${packageName}: Updated CHANGELOG.json`);
         // Generate updated CHANGELOG.md
         const changelogMd = changelogUtils.generateChangelogMd(changelog);
-        const changelogMdPath = path.join(lernaPackage.location, 'CHANGELOG.md');
-        fs.writeFileSync(changelogMdPath, changelogMd);
-        await utils.prettifyAsync(changelogMdPath, constants.monorepoRootPath);
+        await changelogUtils.writeChangelogMdFileAsync(lernaPackage.location, changelogMd);
         utils.log(`${packageName}: Updated CHANGELOG.md`);
     }
 
@@ -217,12 +211,16 @@ async function lernaPublishAsync(packageToVersionChange: { [name: string]: strin
 }
 
 function updateVersionNumberIfNeeded(currentVersion: string, proposedNextVersion: string): string {
+    const updatedVersionIfValid = semver.inc(currentVersion, 'patch');
+    if (_.isNull(updatedVersionIfValid)) {
+        throw new Error(`Encountered invalid semver: ${currentVersion}`);
+    }
     if (proposedNextVersion === currentVersion) {
-        return utils.getNextPatchVersion(currentVersion);
+        return updatedVersionIfValid;
     }
     const sortedVersions = semverSort.desc([proposedNextVersion, currentVersion]);
     if (sortedVersions[0] !== proposedNextVersion) {
-        return utils.getNextPatchVersion(currentVersion);
+        return updatedVersionIfValid;
     }
     return proposedNextVersion;
 }
diff --git a/packages/monorepo-scripts/src/remove_tags.ts b/packages/monorepo-scripts/src/remove_tags.ts
deleted file mode 100644
index 50e413495..000000000
--- a/packages/monorepo-scripts/src/remove_tags.ts
+++ /dev/null
@@ -1,57 +0,0 @@
-#!/usr/bin/env node
-
-import * as _ from 'lodash';
-import * as path from 'path';
-import { exec as execAsync } from 'promisify-child-process';
-import semverSort = require('semver-sort');
-
-import { constants } from './constants';
-import { Changelog } from './types';
-import { utils } from './utils/utils';
-
-(async () => {
-    const shouldIncludePrivate = true;
-    const updatedPublicLernaPackages = await utils.getUpdatedLernaPackagesAsync(shouldIncludePrivate);
-
-    for (const lernaPackage of updatedPublicLernaPackages) {
-        const packageName = lernaPackage.package.name;
-        const currentVersion = lernaPackage.package.version;
-        const changelogJSONPath = path.join(lernaPackage.location, 'CHANGELOG.json');
-        // Private packages don't have changelogs, and their versions are always incremented
-        // by a patch version.
-        const changelogJSONIfExists = utils.getChangelogJSONIfExists(changelogJSONPath);
-
-        let latestChangelogVersion: string;
-        if (!_.isUndefined(changelogJSONIfExists)) {
-            let changelogs: Changelog;
-            try {
-                changelogs = JSON.parse(changelogJSONIfExists);
-            } catch (err) {
-                throw new Error(
-                    `${lernaPackage.package.name}'s CHANGELOG.json contains invalid JSON. Please fix and try again.`,
-                );
-            }
-            latestChangelogVersion = changelogs[0].version;
-        } else {
-            latestChangelogVersion = utils.getNextPatchVersion(currentVersion);
-        }
-
-        const sortedVersions = semverSort.desc([latestChangelogVersion, currentVersion]);
-        if (sortedVersions[0] === latestChangelogVersion && latestChangelogVersion !== currentVersion) {
-            const tagName = `${packageName}@${latestChangelogVersion}`;
-            try {
-                await execAsync(`git tag -d ${tagName}`, { cwd: constants.monorepoRootPath });
-                utils.log(`removed tag: ${tagName}`);
-            } catch (err) {
-                if (_.includes(err.message, 'not found')) {
-                    utils.log(`Could not find tag: ${tagName}`);
-                } else {
-                    throw err;
-                }
-            }
-        }
-    }
-})().catch(err => {
-    utils.log(err);
-    process.exit(1);
-});
diff --git a/packages/monorepo-scripts/src/types.ts b/packages/monorepo-scripts/src/types.ts
index 36fb923b3..61bd75732 100644
--- a/packages/monorepo-scripts/src/types.ts
+++ b/packages/monorepo-scripts/src/types.ts
@@ -27,3 +27,16 @@ export enum SemVerIndex {
 export interface PackageToVersionChange {
     [name: string]: string;
 }
+
+export interface PackageRegistryJson {
+    versions: {
+        [version: string]: any;
+    };
+    time: {
+        [version: string]: string;
+    };
+}
+
+export interface GitTagsByPackageName {
+    [packageName: string]: string[];
+}
diff --git a/packages/monorepo-scripts/src/utils/changelog_utils.ts b/packages/monorepo-scripts/src/utils/changelog_utils.ts
index edfe65a80..dbafb6f16 100644
--- a/packages/monorepo-scripts/src/utils/changelog_utils.ts
+++ b/packages/monorepo-scripts/src/utils/changelog_utils.ts
@@ -1,6 +1,11 @@
+import * as fs from 'fs';
 import * as _ from 'lodash';
 import * as moment from 'moment';
+import * as path from 'path';
+import { exec as execAsync } from 'promisify-child-process';
+import semver = require('semver');
 
+import { constants } from '../constants';
 import { Change, Changelog, VersionChangelog } from '../types';
 
 const CHANGELOG_MD_HEADER = `
@@ -44,12 +49,58 @@ export const changelogUtils = {
 
         return changelogMd;
     },
-    shouldAddNewChangelogEntry(currentVersion: string, changelog: Changelog): boolean {
+    shouldAddNewChangelogEntry(packageName: string, currentVersion: string, changelog: Changelog): boolean {
         if (_.isEmpty(changelog)) {
             return true;
         }
         const lastEntry = changelog[0];
+        if (semver.lt(lastEntry.version, currentVersion)) {
+            throw new Error(
+                `Found CHANGELOG version lower then current package version. ${packageName} current: ${currentVersion}, Changelog: ${
+                    lastEntry.version
+                }`,
+            );
+        }
         const isLastEntryCurrentVersion = lastEntry.version === currentVersion;
         return isLastEntryCurrentVersion;
     },
+    getChangelogJSONIfExists(changelogPath: string): string | undefined {
+        try {
+            const changelogJSON = fs.readFileSync(changelogPath, 'utf-8');
+            return changelogJSON;
+        } catch (err) {
+            return undefined;
+        }
+    },
+    getChangelogOrCreateIfMissing(packageName: string, packageLocation: string): Changelog {
+        const changelogJSONPath = path.join(packageLocation, 'CHANGELOG.json');
+        let changelogJsonIfExists = this.getChangelogJSONIfExists(changelogJSONPath);
+        if (_.isUndefined(changelogJsonIfExists)) {
+            // If none exists, create new, empty one.
+            changelogJsonIfExists = '[]';
+            fs.writeFileSync(changelogJSONPath, changelogJsonIfExists);
+        }
+        let changelog: Changelog;
+        try {
+            changelog = JSON.parse(changelogJsonIfExists);
+        } catch (err) {
+            throw new Error(`${packageName}'s CHANGELOG.json contains invalid JSON. Please fix and try again.`);
+        }
+        return changelog;
+    },
+    async writeChangelogJsonFileAsync(packageLocation: string, changelog: Changelog): Promise<void> {
+        const changelogJSONPath = path.join(packageLocation, 'CHANGELOG.json');
+        fs.writeFileSync(changelogJSONPath, JSON.stringify(changelog, null, '\t'));
+        await this.prettifyAsync(changelogJSONPath, constants.monorepoRootPath);
+    },
+    async writeChangelogMdFileAsync(packageLocation: string, changelogMdString: string): Promise<void> {
+        const changelogMarkdownPath = path.join(packageLocation, 'CHANGELOG.md');
+        fs.writeFileSync(changelogMarkdownPath, changelogMdString);
+        await this.prettifyAsync(changelogMarkdownPath, constants.monorepoRootPath);
+    },
+    async prettifyAsync(filePath: string, cwd: string): Promise<void> {
+        await execAsync(`prettier --write ${filePath} --config .prettierrc`, {
+            cwd,
+        });
+    },
 };
diff --git a/packages/monorepo-scripts/src/utils/npm_utils.ts b/packages/monorepo-scripts/src/utils/npm_utils.ts
new file mode 100644
index 000000000..cc1e046e7
--- /dev/null
+++ b/packages/monorepo-scripts/src/utils/npm_utils.ts
@@ -0,0 +1,28 @@
+import 'isomorphic-fetch';
+import * as _ from 'lodash';
+
+import { PackageRegistryJson } from '../types';
+
+const NPM_REGISTRY_BASE_URL = 'https://registry.npmjs.org';
+const SUCCESS_STATUS = 200;
+const NOT_FOUND_STATUS = 404;
+
+export const npmUtils = {
+    async getPackageRegistryJsonIfExistsAsync(packageName: string): Promise<PackageRegistryJson | undefined> {
+        const url = `${NPM_REGISTRY_BASE_URL}/${packageName}`;
+        const response = await fetch(url);
+
+        if (response.status === NOT_FOUND_STATUS) {
+            return undefined;
+        } else if (response.status !== SUCCESS_STATUS) {
+            throw new Error(`Request to ${url} failed. Check your internet connection and that npmjs.org is up.`);
+        }
+        const packageRegistryJson = await response.json();
+        return packageRegistryJson;
+    },
+    getPreviouslyPublishedVersions(packageRegistryJson: PackageRegistryJson): string[] {
+        const timeWithOnlyVersions = _.omit(packageRegistryJson.time, ['modified', 'created']);
+        const versions = _.keys(timeWithOnlyVersions);
+        return versions;
+    },
+};
diff --git a/packages/monorepo-scripts/src/utils/utils.ts b/packages/monorepo-scripts/src/utils/utils.ts
index 0b8ac4c0b..20bc57bae 100644
--- a/packages/monorepo-scripts/src/utils/utils.ts
+++ b/packages/monorepo-scripts/src/utils/utils.ts
@@ -1,27 +1,17 @@
-import * as fs from 'fs';
 import lernaGetPackages = require('lerna-get-packages');
 import * as _ from 'lodash';
 import { exec as execAsync } from 'promisify-child-process';
+import semver = require('semver');
 
 import { constants } from '../constants';
-import { UpdatedPackage } from '../types';
+import { GitTagsByPackageName, UpdatedPackage } from '../types';
+
+import { changelogUtils } from './changelog_utils';
 
 export const utils = {
     log(...args: any[]): void {
         console.log(...args); // tslint:disable-line:no-console
     },
-    getNextPatchVersion(currentVersion: string): string {
-        const versionSegments = currentVersion.split('.');
-        const patch = _.parseInt(_.last(versionSegments) as string);
-        const newPatch = patch + 1;
-        const newPatchVersion = `${versionSegments[0]}.${versionSegments[1]}.${newPatch}`;
-        return newPatchVersion;
-    },
-    async prettifyAsync(filePath: string, cwd: string): Promise<void> {
-        await execAsync(`prettier --write ${filePath} --config .prettierrc`, {
-            cwd,
-        });
-    },
     async getUpdatedLernaPackagesAsync(shouldIncludePrivate: boolean): Promise<LernaPackage[]> {
         const updatedPublicPackages = await this.getLernaUpdatedPackagesAsync(shouldIncludePrivate);
         const updatedPackageNames = _.map(updatedPublicPackages, pkg => pkg.name);
@@ -43,22 +33,86 @@ export const utils = {
         }
         return updatedPackages;
     },
-    getChangelogJSONIfExists(changelogPath: string): string | undefined {
-        try {
-            const changelogJSON = fs.readFileSync(changelogPath, 'utf-8');
-            return changelogJSON;
-        } catch (err) {
-            return undefined;
+    async getNextPackageVersionAsync(
+        currentVersion: string,
+        packageName: string,
+        packageLocation: string,
+    ): Promise<string> {
+        let nextVersionIfValid;
+        const changelog = changelogUtils.getChangelogOrCreateIfMissing(packageName, packageLocation);
+        if (_.isEmpty(changelog)) {
+            nextVersionIfValid = semver.inc(currentVersion, 'patch');
+        }
+        const lastEntry = changelog[0];
+        nextVersionIfValid = semver.eq(lastEntry.version, currentVersion)
+            ? semver.inc(currentVersion, 'patch')
+            : lastEntry.version;
+        if (_.isNull(nextVersionIfValid)) {
+            throw new Error(`Encountered invalid semver: ${currentVersion} associated with ${packageName}`);
         }
+        return nextVersionIfValid;
     },
-    getChangelogJSONOrCreateIfMissing(changelogPath: string): string {
-        const changelogIfExists = this.getChangelogJSONIfExists(changelogPath);
-        if (_.isUndefined(changelogIfExists)) {
-            // If none exists, create new, empty one.
-            const emptyChangelogJSON = JSON.stringify([]);
-            fs.writeFileSync(changelogPath, emptyChangelogJSON);
-            return emptyChangelogJSON;
+    async getRemoteGitTagsAsync(): Promise<string[]> {
+        const result = await execAsync(`git ls-remote --tags`, {
+            cwd: constants.monorepoRootPath,
+        });
+        const tagsString = result.stdout;
+        const tagOutputs: string[] = tagsString.split('\n');
+        const tags = _.compact(
+            _.map(tagOutputs, tagOutput => {
+                const tag = tagOutput.split('refs/tags/')[1];
+                // Tags with `^{}` are duplicateous so we ignore them
+                // Source: https://stackoverflow.com/questions/15472107/when-listing-git-ls-remote-why-theres-after-the-tag-name
+                if (_.endsWith(tag, '^{}')) {
+                    return undefined;
+                }
+                return tag;
+            }),
+        );
+        return tags;
+    },
+    async getLocalGitTagsAsync(): Promise<string[]> {
+        const result = await execAsync(`git tags`, {
+            cwd: constants.monorepoRootPath,
+        });
+        const tagsString = result.stdout;
+        const tags = tagsString.split('\n');
+        return tags;
+    },
+    async getGitTagsByPackageNameAsync(packageNames: string[], gitTags: string[]): Promise<GitTagsByPackageName> {
+        const tagVersionByPackageName: GitTagsByPackageName = {};
+        _.each(gitTags, tag => {
+            const packageNameIfExists = _.find(packageNames, name => {
+                return _.includes(tag, `${name}@`);
+            });
+            if (_.isUndefined(packageNameIfExists)) {
+                return; // ignore tags not related to a package we care about.
+            }
+            const splitTag = tag.split(`${packageNameIfExists}@`);
+            if (splitTag.length !== 2) {
+                throw new Error(`Unexpected tag name found: ${tag}`);
+            }
+            const version = splitTag[1];
+            (tagVersionByPackageName[packageNameIfExists] || (tagVersionByPackageName[packageNameIfExists] = [])).push(
+                version,
+            );
+        });
+        return tagVersionByPackageName;
+    },
+    async removeLocalTagAsync(tagName: string): Promise<void> {
+        const result = await execAsync(`git tag -d ${tagName}`, {
+            cwd: constants.monorepoRootPath,
+        });
+        if (!_.isEmpty(result.stderr)) {
+            throw new Error(`Failed to delete local git tag. Got err: ${result.stderr}`);
+        }
+    },
+    async removeRemoteTagAsync(tagName: string): Promise<void> {
+        const result = await execAsync(`git push origin ${tagName}`, {
+            cwd: constants.monorepoRootPath,
+        });
+        if (!_.isEmpty(result.stderr)) {
+            throw new Error(`Failed to delete remote git tag. Got err: ${result.stderr}`);
         }
-        return changelogIfExists;
     },
 };