diff --git a/dev-infra/utils/testing/BUILD.bazel b/dev-infra/utils/testing/BUILD.bazel
new file mode 100644
index 0000000000..bc24a5a00b
--- /dev/null
+++ b/dev-infra/utils/testing/BUILD.bazel
@@ -0,0 +1,15 @@
+load("@npm_bazel_typescript//:index.bzl", "ts_library")
+
+ts_library(
+    name = "testing",
+    srcs = glob(["*.ts"]),
+    module_name = "@angular/dev-infra-private/utils/testing",
+    visibility = ["//dev-infra:__subpackages__"],
+    deps = [
+        "//dev-infra/utils",
+        "@npm//@types/jasmine",
+        "@npm//@types/minimist",
+        "@npm//@types/node",
+        "@npm//minimist",
+    ],
+)
diff --git a/dev-infra/utils/testing/index.ts b/dev-infra/utils/testing/index.ts
new file mode 100644
index 0000000000..1521532ead
--- /dev/null
+++ b/dev-infra/utils/testing/index.ts
@@ -0,0 +1,11 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+export * from './virtual-git-client';
+export * from './virtual-git-matchers';
+export * from './semver-matchers';
diff --git a/dev-infra/utils/testing/semver-matchers.ts b/dev-infra/utils/testing/semver-matchers.ts
new file mode 100644
index 0000000000..fa38e6af12
--- /dev/null
+++ b/dev-infra/utils/testing/semver-matchers.ts
@@ -0,0 +1,12 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/** Gets a jasmine asymmetric matcher for matching a given SemVer version. */
+export function matchesVersion(versionName: string) {
+  return jasmine.objectContaining({raw: versionName, version: versionName});
+}
diff --git a/dev-infra/utils/testing/virtual-git-client.ts b/dev-infra/utils/testing/virtual-git-client.ts
new file mode 100644
index 0000000000..207347eb1e
--- /dev/null
+++ b/dev-infra/utils/testing/virtual-git-client.ts
@@ -0,0 +1,173 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {SpawnSyncOptions, SpawnSyncReturns} from 'child_process';
+import * as parseArgs from 'minimist';
+
+import {GitClient} from '../git/index';
+
+/** Type describing a Git head. */
+interface GitHead {
+  /** Name of the head. Not defined in a detached state. */
+  branch?: string;
+  /** Ref associated with this head. i.e. the remote base of this head. */
+  ref?: RemoteRef;
+  /** List of commits added to this head (on top of the ref's base). */
+  newCommits: Commit[];
+}
+
+/** Type describing a remote Git ref. */
+export interface RemoteRef {
+  /** Name of the reference. */
+  name: string;
+  /** Repository containing this ref. */
+  repoUrl: string;
+}
+
+/** Type describing a Git commit. */
+export interface Commit {
+  /** Commit message. */
+  message: string;
+  /** List of files included in this commit. */
+  files: string[];
+}
+
+/**
+ * Virtual git client that mocks Git commands and keeps track of the repository state
+ * in memory. This allows for convenient test assertions with Git interactions.
+ */
+export class VirtualGitClient extends GitClient {
+  /** Current Git HEAD that has been previously fetched. */
+  fetchHeadRef: RemoteRef|null = null;
+  /** List of known branches in the repository. */
+  branches: {[branchName: string]: GitHead} = {master: {branch: 'master', newCommits: []}};
+  /** Current checked out HEAD in the repository. */
+  head: GitHead = this.branches['master'];
+  /** List of pushed heads to a given remote ref. */
+  pushed: {remote: RemoteRef, head: GitHead}[] = [];
+
+  /** Override for the actual Git client command execution. */
+  runGraceful(args: string[], options: SpawnSyncOptions = {}): SpawnSyncReturns<string> {
+    const [command, ...rawArgs] = args;
+    switch (command) {
+      case 'push':
+        this._push(rawArgs);
+        break;
+      case 'fetch':
+        this._fetch(rawArgs);
+        break;
+      case 'checkout':
+        this._checkout(rawArgs);
+        break;
+      case 'commit':
+        this._commit(rawArgs);
+        break;
+    }
+
+    // Return a fake spawn sync return value. We error non-gracefully if any command fails
+    // in the tests, so we always return success and stub out the `SpawnSyncReturns` type.
+    return {status: 0, stderr: '', output: [], pid: -1, signal: null, stdout: ''};
+  }
+
+  /** Handler for the `git push` command. */
+  private _push(args: string[]) {
+    const [repoUrl, refspec] = parseArgs(args)._;
+    const ref = this._unwrapRefspec(refspec);
+    const name = ref.destination || ref.source;
+    const existingPush =
+        this.pushed.find(({remote}) => remote.repoUrl === repoUrl && remote.name === name);
+    const pushedHead = this._cloneHead(this.head);
+
+    // Either, update a previously pushed branch, or keep track of a newly
+    // performed branch push. We don't respect the `--force` flag.
+    if (existingPush !== undefined) {
+      existingPush.head = pushedHead;
+    } else {
+      this.pushed.push({remote: {repoUrl, name}, head: pushedHead});
+    }
+  }
+
+  /** Handler for the `git commit` command. */
+  private _commit(rawArgs: string[]) {
+    const args = parseArgs(rawArgs, {string: ['m', 'message']});
+    const message = args['m'] || args['message'];
+    const files = args._;
+    if (!message) {
+      throw Error('No commit message has been specified.');
+    }
+    this.head.newCommits.push({message, files});
+  }
+
+  /** Handler for the `git fetch` command. */
+  private _fetch(rawArgs: string[]) {
+    const args = parseArgs(rawArgs, {boolean: ['f', 'force']});
+    const [repoUrl, refspec] = args._;
+    const force = args['f'] || args['force'];
+    const ref = this._unwrapRefspec(refspec);
+
+    // Keep track of the fetch head, so that it can be checked out
+    // later in a detached state.
+    this.fetchHeadRef = {name: ref.source, repoUrl};
+
+    // If a destination has been specified in the ref spec, add it to the
+    // list of available local branches.
+    if (ref.destination) {
+      if (this.branches[ref.destination] && !force) {
+        throw Error('Cannot override existing local branch when fetching.');
+      }
+      this.branches[ref.destination] = {
+        branch: ref.destination,
+        ref: this.fetchHeadRef,
+        newCommits: []
+      };
+    }
+  }
+
+  /** Handler for the `git checkout` command. */
+  private _checkout(rawArgs: string[]) {
+    const args = parseArgs(rawArgs, {boolean: ['detach', 'B']});
+    const createBranch = args['B'];
+    const detached = args['detach'];
+    const [target] = args._;
+
+    if (target === 'FETCH_HEAD') {
+      if (this.fetchHeadRef === null) {
+        throw Error('Unexpectedly trying to check out "FETCH_HEAD". Not fetch head set.');
+      }
+      this.head = {ref: this.fetchHeadRef, newCommits: []};
+    } else if (this.branches[target]) {
+      this.head = {...this._cloneHead(this.branches[target], detached)};
+    } else if (createBranch) {
+      this.head = this.branches[target] = {branch: target, ...this._cloneHead(this.head, detached)};
+    } else {
+      throw Error(`Unexpected branch checked out: ${target}`);
+    }
+  }
+
+  /**
+   * Unwraps a refspec into the base and target ref names.
+   * https://git-scm.com/docs/git-fetch#Documentation/git-fetch.txt-ltrefspecgt.
+   */
+  private _unwrapRefspec(refspec: string): {source: string, destination?: string} {
+    const [source, destination] = refspec.split(':');
+    if (!destination) {
+      return {source};
+    } else {
+      return {source, destination};
+    }
+  }
+
+  /** Clones the specified Git head with respect to the detached flag. */
+  private _cloneHead(head: GitHead, detached = false): GitHead {
+    return {
+      branch: detached ? undefined : head.branch,
+      ref: head.ref,
+      newCommits: [...head.newCommits],
+    };
+  }
+}
diff --git a/dev-infra/utils/testing/virtual-git-matchers.ts b/dev-infra/utils/testing/virtual-git-matchers.ts
new file mode 100644
index 0000000000..41c021aa6f
--- /dev/null
+++ b/dev-infra/utils/testing/virtual-git-matchers.ts
@@ -0,0 +1,41 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {GithubRepo} from '../git/github';
+
+import {Commit} from './virtual-git-client';
+
+/** Interface describing the match parameters for a virtual Git client push. */
+interface BranchPushMatchParameters {
+  targetRepo: GithubRepo;
+  targetBranch: string;
+  baseRepo: GithubRepo;
+  baseBranch: string;
+  expectedCommits: Commit[]|jasmine.ArrayContaining<Commit>;
+}
+
+/**
+ * Gets a jasmine object matcher for asserting that a virtual Git client push
+ * matches the specified branch push (through the match parameters).
+ */
+export function getBranchPushMatcher(options: BranchPushMatchParameters) {
+  const {targetRepo, targetBranch, baseBranch, baseRepo, expectedCommits} = options;
+  return jasmine.objectContaining({
+    remote: {
+      repoUrl: `https://github.com/${targetRepo.owner}/${targetRepo.name}.git`,
+      name: `refs/heads/${targetBranch}`
+    },
+    head: jasmine.objectContaining({
+      newCommits: expectedCommits,
+      ref: {
+        repoUrl: `https://github.com/${baseRepo.owner}/${baseRepo.name}.git`,
+        name: baseBranch,
+      },
+    })
+  });
+}