Create selector language cheat sheet

[jorgeepc]

Context: as part of the efforts of teaching users how to interact with our Selector Language, we want to provide a Cheat Sheet that helps them understand how queries are built and illustrate common query operations.

AC1: As a user interacting with the Create Test Spec form, I want to click on a See Cheat Sheet link, so I can open a PDF file with details about how to build queries using Tracetest Selector Language.

AC2: As a user seeing the Cheat Sheet, I want to see all the language operations with a description and common examples, so I can understand its functionality.

Language Operations:

• Empty Selector
• Filter by Attributes
  • Equal (=) Operator
  • Contains Operator
  • AND Condition
  • OR Condition
• Pseudo-classes
• Parent-child Relation

[jorgeepc]

Tracetest Selector Language Cheat Sheet

Read the complete documentation for the Tracetest Selector Language here.

The Tracetest Selector Language defines the pattern to select spans to which a set of assertions are then applied.

Tracetest Selectors can be grouped into the following categories based on the type of spans they can select:

Basic selectors

Empty selector

Select all spans in a trace.

Example

// An empty selector is an empty string

Attribute selector

Select all spans that have the given attribute.

Syntax

span[attr = "value"]
span[attr contains "value"]

Examples

// Select all spans of type http
span[tracetest.span.type = "http"]

// Select all spans where the service name contains the word "api"
span[service.name contains "api"]

Grouping selectors

AND operator

Select all the matching spans by applying an AND condition between the given attributes.

Syntax

span[attr1 = "value" attr2 = "value"]

Example

// Select all spans of type http and with service name "cart-api"
span[tracetest.span.type = "http" service.name = "cart-api"]

OR operator

Select all the matching spans by applying an OR condition between the given selectors.

Syntax

span[attr1 = "value"], span[attr2 = "value"]

Example

// Select all spans with service name "api-product" or service name "api-cart"
span[service.name = "api-product"], span[service.name = "api-cart"]

Pseudo-classes

Trace structural pseudo-classes

These pseudo-classes relate to the location of a span within the trace waterfall.

Syntax

// Select the first span from the matching list
span[attr = "value"]:first

// Select the last span from the matching list
span[attr = "value"]:last

// Select a span from the matching list based on a given index (n starts at 1)
span[attr = "value"]:nth_child(n)

Examples

// Select the first span of type http
span[tracetest.span.type = "http"]:first

// Select the last span of type http
span[tracetest.span.type = "http"]:last

// Select the third span of type http
span[tracetest.span.type = "http"]:nth_child(3)

Combinators

Descendant combinator

The “ ” (space) combinator selects spans that are descendants of the first span.

Syntax

span[attr1 = "value"] span[attr2 = "value"]

Example

// Select all spans of type http that are descendants of the span with service name "cart-api"
span[service.name = "cart-api"] span[tracetest.span.type = "http"]

[olha23]

@jorgeepc check the design here please: https://www.figma.com/proto/LBN4SKVPq3ykegrPKbHT2Y/0.7-Release-Tracetest?page-id=454%3A5832&node-id=454%3A5833&viewport=489%2C373%2C0.4&scaling=scale-down-width

[kdhamric]

Loving all this!