This document will become out-of-date quickly, but remains historically relevant until such time as this gem is released with support for non-EOL Ruby only.

faraday v0.17.3 is the first version that stops using &Proc.new for block forwarding, and thus is the oldest version oauth2 is compatible with.

gem "faraday", [">= 0.17.3", "< 3.0"]

Ruby

We use the Github Action ruby/setup-ruby@master to install Ruby, and it has a matrix of supported versions (copied below).

Interpreter	Versions
ruby	1.9.3, 2.0.0, 2.1.9, 2.2, all versions from 2.3.0 until 3.1.1, head, debug, mingw, mswin
jruby	9.1.17.0 - 9.3.3.0, head
truffleruby	19.3.0 - 22.0.0, head
truffleruby+graalvm	21.2.0 - 22.0.0, head

In the naming of gemfiles, we will use the below shorthand for interpreter, and version. Platforms will be represented without modification.

Interpreter	Shorthand
ruby	r
jruby	jr
truffleruby	tr
truffleruby+graalvm	trg

Building onto that, we can add the MRI target spec, since that's what all Rubygems use for minimum version compatibility.

Interpreter + Version	MRI spec	Shorthand
ruby-1.9.3	1.9	r1_9
ruby-2.0.0	2.0	r2_0
ruby-2.1.9	2.1	r2_1
ruby-2.2.x	2.2	r2_2
ruby-2.3.x	2.3	r2_3
ruby-2.4.x	2.4	r2_4
ruby-2.5.x	2.5	r2_5
ruby-2.6.x	2.6	r2_6
ruby-2.7.x	2.7	r2_7
ruby-3.0.x	3.0	r3_0
ruby-3.1.x	3.1	r3_1
ruby-head	3.2	rH3_2
ruby-mingw	(?)	rmin
ruby-mswin	(?)	rMS
jruby-9.1.x.x	2.3	jr9_1-r2_3
jruby-9.2.x.x	2.5	jr9_2-r2_5
jruby-9.3.x.x	2.6	jr9_3-r2_6
jruby-head	2.7	jrH-r2_7
truffleruby-19.3.x	2.5(?)	tr19-r2_5
truffleruby-20.x.x	2.6.5	tr20-r2_6
truffleruby-21.x.x	2.7.4	tr21-r2_7
truffleruby-22.x.x	3.0.2	tr22-r3_0
truffleruby-head	3.1(?)	trH-r3_1
truffleruby+graalvm-21.2.x	2.7.4	trg21-r2_7
truffleruby+graalvm-22.x.x	3.0.2	trg22-r3_0
truffleruby+graalvm-head	3.1(?)	trgH-r3_1

We will run tests on as many of these as possible, in a matrix with each supported major version of faraday, which means 0.17.3+ (as f0), 1.10.x (as f1), 2.2.x (as f2).

Discrete versions of faraday to test against, as of 2025.05.14, with minimum version of Ruby for each:

• 2.9.0, Ruby >= 3.0
• 2.2.0, Ruby >= 2.6
• 1.10.0, Ruby >= 2.4
• 0.17.4, Ruby >= 1.9

❌ - Incompatible ✅ - Official Support 🚧 - Unofficial Support 🤡 - Incidental Compatibility 🙈 - Unknown Compatibility

Shorthand	f0 - 0.17.3+	f1 - 1.10.x	f2 - 2.2.x
r1_9	🤡 f0-r1_9	❌	❌
r2_0	🤡 f0-r2_0	❌	❌
r2_1	🤡 f0-r2_1	❌	❌
r2_2	🤡 f0-r2_2	❌	❌
r2_3	🚧 f0-r2_3	❌	❌
r2_4	🚧 f0-r2_4	🚧 f1-r2_4	❌
r2_5	🚧 f0-r2_5	🚧 f1-r2_5	❌
r2_6	🚧 f0-r2_6	🚧 f1-r2_6	🚧 f2-r2_6
r2_7	✅ f0-r2_7	✅ f1-r2_7	✅ f2-r2_7
r3_0	✅ f0-r3_0	✅ f1-r3_0	✅ f2-r3_0
r3_1	✅ f0-r3_1	✅ f1-r3_1	✅ f2-r3_1
rH3_2	🚧 f0-rH3_2	🚧 f1-rH3_2	🚧 f2-rH3_2
rmin	🙈 f0-rmin	🙈 f1-rmin	🙈 f2-rmin
rMS	🙈 f0-rMS	🙈 f1-rMS	🙈 f2-rMS
jr9_1-r2_3	🚧 f0-jr9_1-r2_3	❌	❌
jr9_2-r2_5	🚧 f0-jr9_2-r2_5	🚧 f1-jr9_2-r2_5	❌
jr9_3-r2_6	✅ f0-jr9_3-r2_6	✅ f1-jr9_3-r2_6	✅ f2-jr9_3-r2_6
jrH-r2_7	🚧 f0-jrH-r2_7	🚧 f1-jrH-r2_7	🚧 f2-jrH-r2_7
tr19-r2_5	🚧 f0-tr19-r2_5	🚧 f1-tr19-r2_5	❌
tr20-r2_6	🚧 f0-tr20-r2_6	🚧 f1-tr20-r2_6	🚧 f2-tr20-r2_6
tr21-r2_7	✅ f0-tr21-r2_7	✅ f1-tr21-r2_7	✅ f2-tr21-r2_7
tr22-r3_0	✅ f0-tr22-r3_0	✅ f1-tr22-r3_0	✅ f2-tr22-r3_0
trH-r3_1	🚧 f0-trH-r3_1	🚧 f1-trH-r3_1	🚧 f2-trH-r3_1
trg21-r2_7	✅ f0-trg21-r2_7	✅ f1-trg21-r2_7	✅ f2-trg21-r2_7
trg22-r3_0	✅ f0-trg22-r3_0	✅ f1-trg22-r3_0	✅ f2-trg22-r3_0
trgH-r3_1	🚧 f0-trgH-r3_1	🚧 f1-trgH-r3_1	🚧 f2-trgH-r3_1