verify-email-snapshots

Name: verify-email-snapshots
Author: Aaronontheweb

316installs98forks

How to install verify-email-snapshots?

aaronontheweb/dotnet-skills/verify-email-snapshots

$npx -y skills add Aaronontheweb/dotnet-skills --skill verify-email-snapshots

Installs into the current project.

Summary

Snapshot test email templates using Verify to catch regressions. Validates rendered HTML output matches approved baseline. Works with MJML templates and any email renderer.

Files · 1

View on GitHub

SKILL.md

1	# Snapshot Testing Email Templates with Verify
2
3	## When to Use This Skill
4
5	Use this skill when:
6	- Testing email template rendering for regressions
7	- Validating MJML templates compile to expected HTML
8	- Reviewing email changes in code review (diffs are visual)
9	- Ensuring variable substitution works correctly
10
11	Related skills:
12	- `aspnetcore/mjml-email-templates` - MJML template authoring
13	- `aspire/mailpit-integration` - Test email delivery locally
14	- `testing/snapshot-testing` - General Verify patterns
15
16	---
17
18	## Why Snapshot Test Emails?
19
20	Email templates are:
21	1. Visual - Small changes can break rendering across clients
22	2. Hard to unit test - Output is complex HTML, not simple values
23	3. Prone to regression - Template changes can have unintended effects
24
25	Snapshot testing captures the rendered HTML and fails when it changes unexpectedly.
26
27	---
28
29	## Installation
30
31	```bash
32	dotnet add package Verify.Xunit # or Verify.NUnit, Verify.MSTest
33	```
34
35	---
36
37	## Basic Email Snapshot Test
38
39	```csharp
40	[Fact]
41	public async Task UserSignupInvitation_RendersCorrectly()
42	{
43	// Arrange
44	var renderer = _services.GetRequiredService<IMjmlTemplateRenderer>();
45
46	var variables = new Dictionary<string, string>
47	{
48	{ "PreviewText", "You've been invited to join Acme Corp" },
49	{ "OrganizationName", "Acme Corporation" },
50	{ "InviteeName", "John Doe" },
51	{ "InviterName", "Jane Admin" },
52	{ "InvitationLink", "https://example.com/invite/abc123" },
53	{ "ExpirationDate", "December 31, 2025" }
54	};
55
56	// Act
57	var html = await renderer.RenderTemplateAsync(
58	"UserInvitations/UserSignupInvitation",
59	variables);
60
61	// Assert
62	await Verify(html, extension: "html");
63	}
64	```
65
66	This creates `UserSignupInvitation_RendersCorrectly.verified.html` on first run.
67
68	---
69
70	## Reviewing Email Changes
71
72	When a template changes, the test fails with a diff. Review options:
73
74	### 1. Visual Diff Tool
75
76	```bash
77	# Configure diff tool (one-time)
78	dotnet tool install -g verify.tool
79	verify accept # Accept all pending changes
80	verify review # Open diff tool
81	```
82
83	### 2. Browser Preview
84
85	Open the `.received.html` file in a browser to see the actual rendering.
86
87	### 3. IDE Integration
88
89	Most IDEs show inline diffs for `.verified.html` vs `.received.html` files.
90
91	---
92
93	## Test Each Template Variant
94
95	Create tests for each email template to catch regressions:
96
97	```csharp
98	public class EmailTemplateSnapshotTests : IClassFixture<EmailTestFixture>
99	{
100	private readonly IMjmlTemplateRenderer _renderer;
101
102	public EmailTemplateSnapshotTests(EmailTestFixture fixture)
103	{
104	_renderer = fixture.Services.GetRequiredService<IMjmlTemplateRenderer>();
105	}
106
107	[Fact]
108	public async Task WelcomeEmail_NewUser() =>
109	await VerifyTemplate("Welcome/NewUser", new Dictionary<string, string>
110	{
111	{ "UserName", "John Doe" },
112	{ "LoginUrl", "https://example.com/login" }
113	});
114
115	[Fact]
116	public async Task WelcomeEmail_InvitedUser() =>
117	await VerifyTemplate("Welcome/InvitedUser", new Dictionary<string, string>
118	{
119	{ "UserName", "John Doe" },
120	{ "InviterName", "Jane Admin" },
121	{ "OrganizationName", "Acme Corp" }
122	});
123
124	[Fact]
125	public async Task PasswordReset() =>
126	await VerifyTemplate("PasswordReset/PasswordReset", new Dictionary<string, string>
127	{
128	{ "UserName", "John Doe" },
129	{ "ResetLink", "https://example.com/reset/abc123" },
130	{ "ExpirationMinutes", "30" }
131	});
132
133	[Fact]
134	public async Task PaymentReceipt() =>
135	await VerifyTemplate("Billing/PaymentReceipt", new Dictionary<string, string>
136	{
137	{ "UserName", "John Doe" },
138	{ "Amount", "$10.00" },
139	{ "InvoiceNumber", "INV-2025-001" },
140	{ "Date", "January 15, 2025" }
141	});
142
143	private async Task VerifyTemplate(
144	string templateName,
145	Dictionary<string, string> variables)
146	{
147	var html = await _renderer.RenderTemplateAsync(templateName, variables);
148	await Verify(html, extension: "html")
149	.UseMethodName(templateName.Replace("/", "_"));
150	}
151	}
152	```
153
154	---
155
156	## Scrubbing Dynamic Values
157
158	Some values change between test runs. Scrub them:
159
160	```csharp
161	[Fact]
162	public async Task EmailWithTimestamp_ScrubsDynamicValues()
163	{
164	var html = await _renderer.RenderTemplateAsync("Welcome", variables);
165
166	await Verify(html, extension: "html")
167	.ScrubLinesContaining("Generated at:")
168	.ScrubInlineGuids(); // Scrubs GUIDs in URLs
169	}
170	```
171
172	### Common Scrubbers
173
174	```csharp
175	// Scrub dates
176	.ScrubLinesContaining("Date:")
177	.AddScrubber(s => Regex.Replace(s, @"\d{4}-\d{2}-\d{2}", "SCRUBBED-DAT

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verify-email-snapshots

316installs98forks

View on GitHub

How to install verify-email-snapshots?

aaronontheweb/dotnet-skills/verify-email-snapshots

$npx -y skills add Aaronontheweb/dotnet-skills --skill verify-email-snapshots

Installs into the current project.

Summary

Snapshot test email templates using Verify to catch regressions. Validates rendered HTML output matches approved baseline. Works with MJML templates and any email renderer.

Files · 1

View on GitHub

SKILL.md

1	# Snapshot Testing Email Templates with Verify
2
3	## When to Use This Skill
4
5	Use this skill when:
6	- Testing email template rendering for regressions
7	- Validating MJML templates compile to expected HTML
8	- Reviewing email changes in code review (diffs are visual)
9	- Ensuring variable substitution works correctly
10
11	Related skills:
12	- `aspnetcore/mjml-email-templates` - MJML template authoring
13	- `aspire/mailpit-integration` - Test email delivery locally
14	- `testing/snapshot-testing` - General Verify patterns
15
16	---
17
18	## Why Snapshot Test Emails?
19
20	Email templates are:
21	1. Visual - Small changes can break rendering across clients
22	2. Hard to unit test - Output is complex HTML, not simple values
23	3. Prone to regression - Template changes can have unintended effects
24
25	Snapshot testing captures the rendered HTML and fails when it changes unexpectedly.
26
27	---
28
29	## Installation
30
31	```bash
32	dotnet add package Verify.Xunit # or Verify.NUnit, Verify.MSTest
33	```
34
35	---
36
37	## Basic Email Snapshot Test
38
39	```csharp
40	[Fact]
41	public async Task UserSignupInvitation_RendersCorrectly()
42	{
43	// Arrange
44	var renderer = _services.GetRequiredService<IMjmlTemplateRenderer>();
45
46	var variables = new Dictionary<string, string>
47	{
48	{ "PreviewText", "You've been invited to join Acme Corp" },
49	{ "OrganizationName", "Acme Corporation" },
50	{ "InviteeName", "John Doe" },
51	{ "InviterName", "Jane Admin" },
52	{ "InvitationLink", "https://example.com/invite/abc123" },
53	{ "ExpirationDate", "December 31, 2025" }
54	};
55
56	// Act
57	var html = await renderer.RenderTemplateAsync(
58	"UserInvitations/UserSignupInvitation",
59	variables);
60
61	// Assert
62	await Verify(html, extension: "html");
63	}
64	```
65
66	This creates `UserSignupInvitation_RendersCorrectly.verified.html` on first run.
67
68	---
69
70	## Reviewing Email Changes
71
72	When a template changes, the test fails with a diff. Review options:
73
74	### 1. Visual Diff Tool
75
76	```bash
77	# Configure diff tool (one-time)
78	dotnet tool install -g verify.tool
79	verify accept # Accept all pending changes
80	verify review # Open diff tool
81	```
82
83	### 2. Browser Preview
84
85	Open the `.received.html` file in a browser to see the actual rendering.
86
87	### 3. IDE Integration
88
89	Most IDEs show inline diffs for `.verified.html` vs `.received.html` files.
90
91	---
92
93	## Test Each Template Variant
94
95	Create tests for each email template to catch regressions:
96
97	```csharp
98	public class EmailTemplateSnapshotTests : IClassFixture<EmailTestFixture>
99	{
100	private readonly IMjmlTemplateRenderer _renderer;
101
102	public EmailTemplateSnapshotTests(EmailTestFixture fixture)
103	{
104	_renderer = fixture.Services.GetRequiredService<IMjmlTemplateRenderer>();
105	}
106
107	[Fact]
108	public async Task WelcomeEmail_NewUser() =>
109	await VerifyTemplate("Welcome/NewUser", new Dictionary<string, string>
110	{
111	{ "UserName", "John Doe" },
112	{ "LoginUrl", "https://example.com/login" }
113	});
114
115	[Fact]
116	public async Task WelcomeEmail_InvitedUser() =>
117	await VerifyTemplate("Welcome/InvitedUser", new Dictionary<string, string>
118	{
119	{ "UserName", "John Doe" },
120	{ "InviterName", "Jane Admin" },
121	{ "OrganizationName", "Acme Corp" }
122	});
123
124	[Fact]
125	public async Task PasswordReset() =>
126	await VerifyTemplate("PasswordReset/PasswordReset", new Dictionary<string, string>
127	{
128	{ "UserName", "John Doe" },
129	{ "ResetLink", "https://example.com/reset/abc123" },
130	{ "ExpirationMinutes", "30" }
131	});
132
133	[Fact]
134	public async Task PaymentReceipt() =>
135	await VerifyTemplate("Billing/PaymentReceipt", new Dictionary<string, string>
136	{
137	{ "UserName", "John Doe" },
138	{ "Amount", "$10.00" },
139	{ "InvoiceNumber", "INV-2025-001" },
140	{ "Date", "January 15, 2025" }
141	});
142
143	private async Task VerifyTemplate(
144	string templateName,
145	Dictionary<string, string> variables)
146	{
147	var html = await _renderer.RenderTemplateAsync(templateName, variables);
148	await Verify(html, extension: "html")
149	.UseMethodName(templateName.Replace("/", "_"));
150	}
151	}
152	```
153
154	---
155
156	## Scrubbing Dynamic Values
157
158	Some values change between test runs. Scrub them:
159
160	```csharp
161	[Fact]
162	public async Task EmailWithTimestamp_ScrubsDynamicValues()
163	{
164	var html = await _renderer.RenderTemplateAsync("Welcome", variables);
165
166	await Verify(html, extension: "html")
167	.ScrubLinesContaining("Generated at:")
168	.ScrubInlineGuids(); // Scrubs GUIDs in URLs
169	}
170	```
171
172	### Common Scrubbers
173
174	```csharp
175	// Scrub dates
176	.ScrubLinesContaining("Date:")
177	.AddScrubber(s => Regex.Replace(s, @"\d{4}-\d{2}-\d{2}", "SCRUBBED-DAT

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